Sometimes it's the little things that count? Like the absent-minded touch of a loved one, or a stray beam of sun slipping through thick cloud and illuminating your child as she plays in the park (which is great, because you lost that kid years ago). Or this:
It's my new Lensmate thumbrest and I love it so.
The thumbrest or thumbgrip, which slides just so (all nice and Kentucky, as Douglas Adams might say) into the camera's hotshoe, is the accessory you never knew you needed. The extra bit of grip makes handling the camera just that bit more pleasurable, and you'll find yourself taking pictures with greater ease. In practical terms, it's supposed to aid in stabilization and help you get better handheld shots with slower shutter speeds. And it does. But for me, it just makes everything a little bit easier.
The thumbrest, you'll be supremely interested (or not) to discover, is sometimes called a Thumbs Up grip. Originally developed for Leica cameras by Match Technical Services, they are, like all things associated with Leica, insanely expensive. No doubt they're a good product, but there's probably no need to spend $125-$150 when the $60 Lensmate (yes, still not cheap, I know) is kicking around.
I have other accessories for my camera - a lens hood, a cable release, the TCL-100 teleconverter - but I use the thumbrest 95% of the time, and I always appreciate what it does. Thanks, tiny piece of milled aluminum.
The Lensmate is also a step up from the grip I've been using (pictured above), a $5 eBay item that felt cheap and squiggled around in my hotshoe like an angry baby in a high chair. It had to be screwed into place, and I knew it wouldn't be long before I lost the tiny Allen key (in fact, I think I have lost it). The Lensmate is machined to slide perfectly into the hotshoe, with silicon padding to protect the contacts and provide extra grip. Additional padding braces it along the body around the toggle dial and the exposure compensation dial. Best of all, the Lensmate is designed to match the camera finish, so it just looks like a part of the camera and not a mutant (and backward) film advance lever.
In conclusion, you should pick one up. Then, just to make your purchase worthwhile, you should get a camera to go with it. Otherwise you'll just be resting your thumb all day long and no one respects a thumb rester.