Inside the Data View Web Part, hyperlinks can be populated with data from the data source. Doing so is really easy, but is unfortunately a little bit difficult to discover. 

1. Insert a Data View Web Part based on your data source
2. Select any of the data values displayed in the Data View
3. Choose Insert
4. Choose Hyperlink
5. Click on Parameters

Now you can write out the URL and append parameters (like foo.aspx?bar={@baz}).

-John