You can see every contribution you made (and edit them) very easily, by clicking on the Track link of your account page (accessible via the My account link on the left side of the screen).

This is very handy if you want to review your venture proposition, see if comments were made on your post on the community blog, and it even works on your buddies! Click on My buddylist, then on the Recent Post tab, and you will see what your close friend contributed to the community recently, with an RSS available!