What is the a good Invite-Friends plugin for websites?

I tried Googling around for a good PHP Plugin/code that enables me to place 开发者_C百科an invite your email contacts on my website (something like LinkedIn's invitation plugin which works for all kinds of networks including GMAIL, Yahoo and Hotmail). Unfortunately, couldn't find any real good ones.

I am fine with both something to send from my own mail server, or using the mailserver of the user, or even a third party mail server.

Could you suggest some?

Thanks!

Have you checked openInviter? I have used it about 2 years ago. Unsure how they fare now, it used to be a mixed experience, but they may have stabilized the service. Check it out: http://openinviter.com/

We get a lot of people asking us that question, and lately we've been recommending Friendbuy's Rodeo widget. It includes CloudSponge functionality for importing address books from all the sources that you mentioned and the widget customization features at Friendbuy are pretty awesome.

Disclaimer: I work for CloudSponge.