I'm implementing a plug-in that's embeddable in different sites (a la Meebo, Wibiya), and I want to use jQuery. Problem is, the site I'm embedding to, may already have a jQuery script loaded. The question is, what's the best approach for this kind of problem: Should I just check if jQuery is already loaded and if so, use the original site's jQuery, otherwise load it myself? If I use this approach, am I not risking comaptibility problems (i.e. the site uses an old version of jQuery)? Should I load jQuery myself (whether it's already loaded or not) and call "jQuery.noConflict(true)" when it's finished loading? If so, how can I make sure that my jQuery has finished loading (hooking to the onLoad event doesn't seem to work all the time, and polling for "jQuery" won't work for obvious reasons)? Should I do something else? Thanks.