I wish I could, I don't know how to get it any further down.
I don't have many apps installed and no apps that do anything in the background particularly.
Gmail (All google sync services)
I dunno what else it could be
2.3.3 has the "Android OS bug" meaning that you need to update to 2.3.4 (or higher). My Captivate had the same issue with 2.3.3.
If you've never been to XDA, I would highly recommend you go read everything you can. There's TONS of custom ROMs for your phone that would fix the OS bug and make your phone much faster than stock.
Be 100% sure you know what you're doing before flashing new firmware.