I decided to stray from the typical Evite for my sister's bachelorette party invitations. After a bit of surfing, I found Pingg. What I like most about it is that it offers nice theme pictures, and gives you the option of uploading your own. Plus you can send via e-mail, sms, etc. and somehow you can connect your invitation to (gulp) Facebook. It also provides a very detailed ticker of every action related to the event and its invitation (i.e. when so-and-so read the invitation, when you added this guest or uploaded a different picture)

I like.