ShareMeme is a free web service which allows you to share items with your friends, no matter which social network they are using. ShareMeme is not a social network but it brings all your contacts at one place. With ShareMeme, you can send invites, polls, and links quickly and easily from a text message or the web through email, IM, text message, Twitter, MySpace, LinkedIn, or Facebook.
The dashboard of ShareMeme has 6 options and you can create a group, link, invitation, poll, reminder or even a note.
The reminder, invitation and Poll feature are really good and the reminder can be set to notify you by email, Gtalk, Twitter and SMS (Available only in US).
With the build in Contacts import feature, you can easily imports your contacts from Windows Live, Gmail, Yahoo and also Twitter. You can also add contacts directly from ShareMeme. The interface of ShareMeme is really good and very easy to create tasks.
You can also subscribe to feed of your recent activities, so that in case someone responds to your tasks, you get notified through feeds.
ShareMeme is definitely a great start up and has good features which makes it easy to share tasks and notes with your friends and tracks the responses. ShareMeme is currently in beta and signup is restricted through invites only. You can request for an invite code here.