If you download Picasa to your Pc you can then either upload to the web albums or download to PC via usb. it gives you the option to remove after downloading or leave on the phone. The web album can be downloaded back to the PC if you go that route. If you download and delete them off your phone should save you some space on your sd. Great way to manage/share your photos as well. I recommend. And you can always view them in your browser on your web album.
Picasa 3: Free download from Google