Several years ago one of the things that was really missing from desktop Linux was the use of USB cameras, which were quickly becoming ubiquitous in both the Mac and Windows world. I spent a fair amount of time downloading, compiling, and tweaking, but it became very clear that USB cameras were not (yet) for Linux.
Fast forward to the present and Ubuntu 8 and Fedora 8. USB cameras have become plug and play thanks to the hard work of OSS developers (thanks!). And now that USB cameras have been incorporated into the Linux experience, we have Cheese, a USB camera utility to take pictures and videos from your USB camera (a la Mac). Developed by Daniel G. Diegel and Jaap A. Haitsma , this program is a great tool for engaging your kids (and having some fun yourself).
While it doesn't seem to have made it into the standard builds for Ubuntu or Fedora, it can be installed on each (apt-get install cheese, or yum install cheese). Its a great little tool and a must have for anyone using desktop Linux at home.