RYX, the original author of screenlets is apparently MIA, so Whise has continued development on Screenlets, making them even better. He now merged with trunk, after not getting feedback from RYX for a while.
I use bzr to get the latest and greatest, but I wrote a howto on setting up for Gilir’s Ubuntu repo. See this thread on the Screenlets forums (which is located on Compiz Fusion forums) or check the Screenlets wiki (help out getting rid of the spam if there is any!)
My approach is using bzr. In order to do that, do:
bzr co http://bazaar.launchpad.net/~screenlets-dev/screenlets/trunk screenlets
sudo python setup.py install
sudo python setup.py install (if there were updates)