Six degrees of wikiation
Another simple IM game.
In this one, each player picks a wikipedia page. When both have picked a page, they race to see who can connect the two pages using only links on either page. The first one to get from one page to the other (in either direction) gets the point.
You can add additional rules as desired like “No using the ‘what links here?’ button”, or “no categories”… but it’s pretty much on the honor system.