So maybe this isn't a web app per-se, but we've found out about a pretty cool way to spend some time with your iPhone. It's a web comic. Sure you can view any web comic on your iPhone, but this one is specifically formatted for the iPhone which we thought was really cool!
nemu*nemu is a really cute web comic thats worth reading if you have some time to kill and want something to check out on your iPhone. The style is leans toward "anime" so this may or may not be your cup of tea, but so far we've enjoyed what we've seen. The comic is perfectly formatted for the iPhone in standard position since the comic is done vertically.
Give it a shot... it's funny and it's free!
nemu*nemu iPhone edition can be found http://nemu-nemu.com/iphone/.
