Matt Cutts prefers the trailing slash: SEO advice: url canonicalization

From a more technical standpoint, the trailing slash tells the server to use the default document list for that folder and load that page. Without it the server first looks for a matching document name, then a folder with that name and will then use default doc list, resolving to finally perform a redirect (302) to that document.

so using the trailing slash saves a certain amount of server load and aids the speed the document will load.

generally no, however in some cases it can be considered different. as josh already mentioned, not using the slash will cause two requests, one for the one without then the redirect to the one with the slash.