What tools do you use to help you write?
I for one use Pinterest to help find inspiration for characters, settings, and the like.
I actually just signed up at Pinterest today to try it out for visual inspiration for my NaNoWriMo project.
As far as software goes, pretty much just Word at this point, though I keep hearing about Scrivener and might eventually give them a try one of these days (especially if I win NaNo and get their discount code). I use the occasional name generator to give me syllables to play around with if I’m stuck on a name. I’ve tried sites like One Page a Day (I think it’s called) and Write or Die and Written? Kitten!, but that’s more just for fun every once in a while to try something new, and not anything I use on a regular basis.
Physical tools - my Alphasmart Neo, which I love and highly recommend to everyone who’ll listen, and of course whatever my current journal is, and my current favorite pen.
(And I just went to the Alphasmart site and saw that they’re not producing any more Neos. 
Crap. Looks like it’s eBay for me if/when this current unit dies.)
Well, I’m a Linux user, so the tools I use are rather different.
For stream-of-consciousness brainstorming, I like using gnote, although tomboy is a good alternative (and since tomboy runs on Mono, I think you can even get it to run in Windows). In effect, it gives you the ability to create notes, then link to each other, almost wiki-style. This is a good way to create worlds and environments, letting you organize your notes and quickly access them. Never get caught in a retcon again!
I use LibreOffice for my writing. It can write to and read from .doc and .docx files, so porting over from a windows computer or sending them to a windows computer is no problem at all. Plus a very comprehensive spell checker. Grammar checker is a bit more primitive, but let’s face it… there aren’t many decent ones out there. The best grammar checker I have ever encountered is a good writer’s circle, and wrote memorization of the rules.
The only other tools are my overactive imagination and my keyboard.
Three websites I like to always have at hand when writing are dictionary.com, wikipedia and google. The former is for obvious reasons, with the latter two assisting with last minute fact-checking (my favorite kind!).
I use MSword when available. I don’t have any particular tools for inspiration, unless art is utilitarian enough to be thought of us a tool, but that’s making my brain work and I’m trying to unwind.
In writing furry stories, I like to read books and visit websites on animal behavior. They help me depict my anthro characters better, I feel.
I also love name books and name websites – finding the perfect name for a character really can bring a character to life. Sherrilyn Kenyon’s Character Naming Sourcebook is my first stop. She breaks down names by country of origin. I find that especially helpful when I’m going for a consistent feel for my names.
As long as you don’t expect perfection in all the details, I use Wikipedia a lot too when I want to get a quick overview of a subject.
I do a lot of Google image searches. I find it helpful to have a page of pictures of whatever type of animal I’m writing about in front of me. I also find Google Earth really helpful if I’m writing about a place on Earth. I spent a lot of time wandering around the San Francisco Fisherman’s Wharf in Google Earth while I was working on the story that will come out in the next ROAR. It was really helpful for getting the details right, since I haven’t been there in about a decade.
I write everything in Word, but use Notepad to list ideas, names, notes, etc.
The only other tool is a dictaphone I keep by my bed, since I do my best brainstorming before sleep. I’ll have an idea, and know I’ll forget it by the time I get up.
Inspiration is all me, baby. Google only comes out if I don’t know something.
I take regular breaks so anything that I can distract myself with after certain points could theoretically be a tool.
Actually, another tool I’ve started using recently is Dropbox to synch my iPhone with my laptop, and then I write in an app called Office[sup]2[/sup]. I can set my phone up with a wireless keyboard (I have little plastic doohickeys that clip onto the keyboard and prop the phone up), and it makes for a super light weight, extremely portable writing device. Though, sometimes I skip past the keyboard and just thumb-type on the software keyboard on the phone. That works best if I just want to jot down a couple sentences before falling asleep or if I’m working on a really tricky part of a story where my brain can’t keep up with my hands on a keyboard anyway.
I use a lot of flowcharts. I like to to think of a central idea, then have multiple bubbles form off of that idea, then pick from there, rinse and repeat.
If it wasn’t for the fact that I’ve had to restart stories I’ve been over 100 pages into several times because physical pages got replaced, I’d still be doing all my first drafts by hand. While I can type fast, my fingers move far faster than my brain and I tend to insert words into sentences that have nothing to do with what I’m typing.
I still draft all my stories by hand (pre-writing, maybe not). For some reason, I find that things flow better with that physical contact of hand and pen against paper…
I totally meant to say ‘misplaced’ and not ‘replaced’. I guess that’s what I get for posting here on a smartphone. Damn autocorrect.
I tend to write in plain text rather than in a word processor – usually using Markdown to indicate italics, bold, section breaks and the like – for two main reasons: one, anything can edit it, and two, I can convert it cleanly into almost anything else very simply. The exception to this is when I’m using Scrivener, which a few other people have mentioned.
For other tools, one thing that’s potentially worth looking at is an outline processor; while I use OmniOutliner, there are other ones available for other platforms. Yes, word processors can do outlines, too, but they’re usually pretty awkward compared to dedicated ones, especially if you’re using them for brainstorming. A free web-based one that should be pretty good is Dave Winer’s Fargo; I haven’t tried it, but Winer pretty much created this whole category of software 30 years ago and has gotten pretty good at it. 
And there are also some kind of madcap programs out there designed to help with story construction. These are usually aimed at screenwriters. Blake Synder’s now somewhat infamous Save the Cat! book has a companion story structure application, and there are a few other ones, like Mariner Software’s Contour and Write Brothers’ Dramatica. Of those, Dramatica is the only one I like (Just buy Snyder’s book, and you can literally do everything that Contour’s software can with its manual and a blank piece of paper); it’s expensive and has an astonishingly bad UI, but it’s helped me think a lot about how to put together longer works.
For character names I tend to use baby name web sites; for major characters I occasionally look up words by meanings, although that can get overwrought quickly. They’re good to use for non-English names if you want them to be actual names, as opposed to “string of letters I think sound Arabic when put together” or “Japanese word that sounds cool but that no one in their right mind would ever name their child”.