Modding/Guide to backing up saves

There are several reasons to back up your character. Backing up characters often is advisable.
 * It's just a good idea in general.
 * Transference from one system/console to another.
 * Reverting your character to a previous time for repeated farming or testing.
 * Keeping originals when manipulating or modding.

Step by step guide
PC: Make a new folder labeled "borderlands back up" or something similar. Open the file located in: My Documents/My Games/Borderlands/SaveData. Press Ctrl+A (select all) then Ctrl+C (copy). Open the folder "borderlands back up" and press Ctrl+V (paste).
 * To make multiple "time shots" just make multiple folders.

Xbox: STUB please add content

PS3: STUB please add content (and is it even possible?)

Strategy
Farming: When doing runs that only happen once, such as farming King Wee Wee for a good Wee Wee's Super Booster, you can overwrite your character to repeat the run. Once you get a decent drop, you can copy the character in another folder and overwrite again for multiple items.

Testing: You can keep tests consistent by overwriting your character and repeating exact circumstances.

Manipulating: You should always back up the entire folder before manipulating anything in it. By definition, manipulation can mess thing up.