How do I create a custom bookmark that grabs the current URL?

Your question is a bit confusing, yes, but I know what you mean because a few months ago I wrote a similar sort of utility that let me disseminate my favorite sites into an archive system I wrote on my server (yeah, kinda geeky, but, in the immortal words of Popeye, I yam what I yam. :-)

Anyway, here's the Javascript code I wrote for the bookmark itself:

As you can see, it's all a little Javascript trick here, where I'm accessing various elements of the document object model (the "DOM" for insiders), in this case the URL of the current page (that's location.href) and the title of the page too (that's document.title). You can't just slap those onto a new URL, however, so we also use a handy Javascript element called encodeURIComponent to turn spaces into "+", mask control characters and punctuation, etc.

If I was on a page with the URL, say, of "http://www.mypage.com/" and a title of "Interesting Information", then the resultant call to my CGI script would be:

The CGI script then simply needs to unwrap and identify the "u" and "t" variables to extract the URL and title again within the script. This should be easy to accomplish depending on your CGI programming skills.

For your purposes, you probably don't need the title of the page, so your task would be even easier: just delete the "t=" title portion.

In terms of how to get a bookmark set for your complicated Javascript code, the bst solution is to do something like this:

Which would be implemented thusly:

Drag this bookmark onto your toolbar (or, if you prefer, right-click and choose "Bookmark this link" or similar)

That should get you going with your project. Good luck!