What is the best way to parse a web page in Ruby?

I have been looking at XML and HTML libraries on rubyforge for a simple way to pull data out of a web page. For example if I want to parse a user page on stackoverflow how can I get the data into a usable format? Say I want to parse my own user page for my current reputation score and badge listing. I tried to convert the source retrieved from my user page into xml but the conversion failed due to a missing div. I know I could do a string compare and find the text I'm looking for, but there has to be a much better way of doing this. I want to incorporate this into a simple script that spits out my user data at the command line, and possibly expand it into a GUI application.