Well, I wouldn't really recommend you use my code verbatim, but to request a different size replace "320x240" with "640x480", or any other valid size (my team has the axis 206, which I believe only has those two sizes). If you follow what I posted you should see it merely forms the options into a valid URL.
As for framerate, I remember getting 29 or 30 fps w/ processing on 320x240 resolution. It was closer to 14 or 13 on the larger 640x480. Part of the reason I reverted to grabbing single jpegs was due to the fact I couldn't get a library to decode mjpeg streams working at the time -- also, since we didn't really want a camera readout, the image processing only grabbed frames as it needed them. That didn't end up speeding anything up, but I like to feel... optimized!
