I woke up with a cough last night and couldn't get back to sleep so came downstairs. While doing some surfing (as an aside to this aside, I never turn the TV on at such times anymore), I accidentally hit the return key after just typing in K in the browser. It took me straight to the wikipedia definition of K. Odd, I thought, so I tried L, and that got the wikipedia definition as well. I wondered if wikipedia had the whole alphabet sewn up, so went through each letter. It seems my initial two hits were just beginner's luck. Most single letters (without the addition of any domain entry e.g. .com) returned Google searches, but a few of them went directly to sites. In case you're interested (and I know you are), the following are the lucky letters:
g google mail
k http://en.wikipedia.org/wiki/K
l http://en.wikipedia.org/wiki/L
t http://www.att.com/gen/landing-pages?pid=3308
I then wondered why more single letters don't take you to sites, so looked up single letter domain names. It turns out this was something of a hot issue, with six single letter domain names reserved, but apart from that these the internet governing body has reserved the rest under the .com, .net and .org names. Steve Krause explains http://www.stevekrause.org/steve_krause_blog/2007/02/why_no_singlele.html
This is slightly different, as the ones mentioned above are not the ones reserved, but is based on there being no alternatives for google to find I guess?
Anyway, amazing what you discover at 3am and better than watching the shopping channel surely.