Course if you knew how to use sockets or similar in php you could probably respond to the server telling it the desired refferer. Depends on specifically what you are trying to do and how versed you are in coding among other things (ie: it may not be practical for what you wish to do, depending).
You can also use this FireFox Plugin called RefControl to type in which refferer you want. ("Control what gets sent as the HTTP Referer on a per-site basis. ")
The options above may not help you however if you're looking to mass request a site, in which case you need a coder and some variation in refferer. (I'm sure such site can also track your IP address which isn't as easy to spoof, and its not very pratical to got thru a bunch of proxies)
I think I may have come across a way to 'clean' my traffic now. Thanks for the input anyway guys, I could probably use some of the stuff you've posted for other projects!