Phonevite does party invites by phone, not email
Send out massive invitations by phone using Phonevite.
Phonevite is a new free invitation and RSVP service that turns your Web browser into a personal assistant of sorts, letting you call a large group of friends, family, or contacts without having to spend all day on the phone. Instead Phonevite provides an asynchronous solution, giving you an easy way to record a personalized invitation message using your computer's microphone, and send it out to a list of hand-picked phone numbers. From there you can send out the "invitation" right away, or schedule it in for a later date.
When an invitation goes live, Phonevite will call all the numbers you've given it simultaneously. Your recipients (if they're there) will hear your name and recorded invitation and get the option to reply yes, no, or maybe. You can also enable an option for them to record their own voice message that you can listen to via Phonevite's tracking page. That same tracking page also lets you see whether or not the phone call was a success, the recipient's response, and an option to resend the invitation in instances where it failed.
The real Achilles heel of this service is how it handles voice mail. The response feature only works on live calls. Users still get your message, but not a way to respond without having to call you back. Luckily the service spoofs your number, so responding to the voice mail actually sends the call straight to you. Ideally, Phonevite could provide each user their own callback number that would give invitees the option to respond at their leisure.
Phonevite is a really simple service to use. It took me no time to record a message, and begin adding contact numbers (for Outlook buffs there's also the option to import them from a .CSV file). One caveat is the need to use Internet Explorer, as Phonevite's recording and message playback features require an ActiveX plug-in. For calling small- to medium-size groups of people (10 to 25) this service is a great way to garner a quick response. As for providing more publicly available information about and event, like an RSVP list, and Web map, I'd stick to Eviteand MyPunchbowl.