This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
They very similar; Python Eggs were essentially a reply to RubyGems, and embody most of the same features; versioning, dependencies, archiving, etc. RubyGems might be slightly more mature than Python Eggs - the Python Eggs dev site lists it as "close to beta quality" - but I definitely wouldn't use either as a reason to choose a language.
Both take essentially the same problem and solve it in more or less the same way.