You can only deactivate your account.
By removing/changing personal info and then deactivating it, you kind of delete it. But it’s still some hassle.
For doing so, log in, use the link (or go to your profile page), optionally change or remove your personal information on any page, then click Account Information (on your left), scroll down, enter password and off you go.
Here you can read how to re-open your deactivated account: http://getsatisfaction.com/getsatisfaction/topics/tip_how_to_restore_a_deleted_getsatisfaction_account