Upload & Sell: On
There have always been theories about where to format, so I want to add my vote that formatting on the computer works very well for me. When I am sure I have a valid transfer and a backup of that transfer done, I format the cards in the computer. I then use them on which ever camera I want, and when they are inserted the camera takes a half a second and puts its little file structure on. I never worry about what goes where. This has been working perfectly for me since the Canon 20D and 1D2 era, and now includes primarly the 1DX, 1D4, and 5D2 cameras. I litterly never format in the camera, and I can shift card resources around as a day progresses with no worry about file numbering, no worry about putting the "wrong" card in a camera, and no worry about taking the time to format in camera. Some of what I shoot requires very fast card changes, and the computer formatting helps me do that.
Also the mention of using safe removal all the time by someone else is a step I do not do. For CF cards in card readers on computers, I just wait until I know there is no file activity going on, and then pull the card. The directory structure closes out in the explorer window, and all is well. I have never had a problem with that procedure on my CF cards. I do not ever open files on a CF card other than Explorer file listing and image viewing. I always copy my whole card to the computer before any file work with photo software. For SD cards I have less experience, so I sometimes use safe removal, but often forget, and still no problems.
For USB drives I am a little more careful, depending on what software may have opened what files on the card, and sometimes use safe removal if the files are important or there is no other backup.