Somehow, running FB in Safari on the iPad makes this difficult. I just use the iPhone app on the iPad for uploading pictures to FB, as the previous poster said. For normal browsing and interacting, though, the iPad Safari version wins. I hope FB finds a developer to migrate and enhance the iPhone app for the iPad...
I use the SD card reader in the iPad Camera Connection kit, then email the pics I want to share on FB to my personalized upload email address. You only have to set this up once, the address does not change.