I just answered my own question - I have spent days trying to figure out how to scroll within the gallery from one photo to the next without using the menu key, and just as I was about to ask you guys, I tried pressing "N" for "next" and "P" for previous (I had previously tried space bar, alt keys, etc). Whaddaya know! So easy!
Still learning about my Curve and so far I love it!
OH!!! thank you SOOO much! it's been driving me crazy. i even read the manual and i didn't see it in there. i guess N and P would make sense, if i wasn't so convinced that the trackball would scroll through the pics.