Prototype (like JQuery) uses the $ notation, and so by default any GreaseMonkey User Script loaded will hijack the $ object, meaning that stuff on the original site may stop working.
I thought I was sunk but it turns out JQuery just gets better, and it can gracefully give back control of the $ to whichever library originally loaded it. Just call..
You then have to use jQuery instead of $ (e.g. jQuery(“#myID”) instead of $(“#myID”) ), but hey – that’s a small price to pay when the alternative is rewriting the whole thing long-hand.