Check out Robert’s post at http://www.thorprojects.com/blog/archive/2007/05/16/list-of-features-with-guids.aspx for a quick list of which GUID links to which feature within your MOSS Farm.

In addition, StefanG has a tool on msdn (http://code.msdn.microsoft.com/WssAnalyzeFeatures) which will list out the guid and feature that you have installed on your site collection. Very helpful!