I recently stumbled upon the site of Paul Graham, who is one of the three guys that created maybe the first online store, now sold to Y!. I like his essays very much and highly recommend them to everybody who has something to do with the web or programming. Part of his essays are listed on his site and part are in his book, "Hackers and Painters"
I wanted to print some of the essays to read on my train ride, but I saw that the text on the pages is in a narrow fixed width table column, which is a waste of paper when you print (and also thicker and heavier to carry ;)) Let me show you how I used a bookmarklet available from the squarefree.com collection to fix this problem.
1) The page in question, viewed 800x600 pixels (these are all clickable thumbnails, btw)
2) Print preview shows 25 pages and a lot of blank space on the right
3) Enters Edit Page bookmarklet
4) See these squares, they mark the edges of the content table. The orange dot is for removing a column. We remove the nav menu, we don't need it.
5) The menu's gone, we've played around with the date and the title of the article, just because we can Now we'll be dragging that black square.
6) Dragging... until we think fits.
7) The result.
This is 16 pages, where the last one is just a footer, so it's 15. 15 pages vs. 25, not bad for a few clicks! Long live the bookmarklets!