Makeshift loom to make friendship bracelets...

[JazzyComposition]

Plank of wood, 4 scews at each end, strong thread going from one end screw to other end screw until you have several parallel threads, and then run chosen colour thread through parallel threads but horizontally, down up down up.... something like that anyway, or could somebody tell me how it goes

I have only ever known them made by hand...never heard of a loom for them. Wouldn't it be even fiddlier?

I just use a clip board to hold the threads in place if I'm making a simple woven one. If you're doing a beaded one, then yes, you'd need a loom and one like you've suggested might do the trick, but you can buy really cheap ones from Hobbycraft or eBay (they cost a few £'s, but much less hassle).