The thing that's so interesting about the proxomitron is the fact that any piece of client-side data can be manipulated.
So you can replace a sites cascading style sheet with one of your own, were you to not like their choice in colors or fonts.
On the negative side, javascript games or authentication processes are wide open to the user, even moreso than before.
Thus saying "I'm authorized!" in java has never been so easy.
Thus why you should never ever used client-side scripting for user athentication, no matter how you handle redirections.
A really fun use is just altering a site, and see what it does.
For instance, ever wondered how POST actually works?
Just find an online form, have proxomitron change the location of the form action method to your own page (I just added a "print STDIN;" line to one of my perl cgi environment variable checkers) and see how it does work.
Using the data I got from that I figured out that you can simulate use of a form button on another site, using only fopen() in one of your own PHP scripts.
So technically you could then do an AltaVista search on keywords the user selects, read the data into your own program, alter it to make it look like you created the data, then post up the results.
Of course that would violate various ethical beliefs, but there are plenty of nifty uses like rearranging another site to make it look like YOU think it should look.
Software should run like you want it to, and so should internet sites 😉
So thusly, you could automatically change all banners from some of the well known banner servers to a blank picture, of even a picture of yourself 🙂
Decrease load time and make yourself happy, hehe.
Plus you can manipulate outgoing headers to make your browser version what you want it to be (for sites that misuse browsercap.inis), disable those friggin' java popup windows that people like to use constantly (like on geocities or hypermart...for your viewing pleasure), and you can even disable that Yahoo! adsquare (what masacistic bastard came up with that one?).
If it's in the source code, you can change it!
For instance, sites that use the "private" option to remove your browsers toolbar and menus? Don't you hate that? You can change that too 😉
Bookmark the previously unbookmarkable, and view it's source too. (and kill those stupid right-click killing java scripts while your at it)
Yes, this is the kind of thing I spend my time on. Rather than find sites that do a good job of design, I force them to bend to my will.
One of the many reasons Bill Gate's is my hero, and why I'm at home on a saturday night without a woman.
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...I should probably have proxomitron edit out that last part. Or backspace would work too...