I installed and configured the gallery2 plug-in today for Wordpress 2.0. I used the classic gallery 2 theme with the zen minimalist wordpress theme. There were a few tricks to get things working.
First of all, you need to have url paths turned off in order for gallery to show images inside the wordpress theme. Also it may be necessary to set a minimum size for pictures to prevent a larger picture from breaking your page….obviously depending on the template that you use. Feel free to email me for help.