I don’t use a ton of third-party software, although I’ve got four screens of games after this, but I almost never play them. The original “Library” app I did is up there, even though Amazon made me pull it from the Apple Store — six months of my life wasted, grr.
I decided that the second-most commonly-used apps should be on the second-to-bottom row, so I put Maps, Tweets, Stocks, and Camera there, since I use those almost every day. I have to check my Apple stock daily, and I like to read tweets whenever I get a little down time — although I use Twitterific on the Mac, Tweetie was faster than Twitterific when I first started tweeting on my iPhone, and I’m not super-religious about brands.
I just got “Schlage iLiNK” (ugh stupid name) two nights ago - it lets me check my webcams(!), turn on and off lights, set the temperature in my house, and unlock my doors from anywhere in the world! That’s pretty amazing, and some of it is actually useful. (It’s also part of some research I’m doing for a possible upcoming Delicious product.)
I love iTunes Remote - I have six Airports in my house (most with speakers attached), a wall-mounted iMac in my kitchen that has my master iTunes collection on it, and an Apple TV. Remote lets me control all these things from wherever I am in the house, so I can play whatever music wherever. It’s one of those apps that feels like the future.