a few ideas for the future:

1) When you have just unlocked the ability to use a new item for your avatar send a notification i.e.
"XXXXXX just +1 Your comment, you can now get a pet tiger!"
or
"XXXXXX just +1 Your comment, you can now choose a new t-shirt"

2) Rant categories, i.e. Clients, colleagues, OS, jokes, !rant etc...

3) the ability to view more then the last 30 rants of a users profile