do you know if there's some way to put in more than three or four skyscraper ad-sets, or some other way to get ads running down the length of a very long page?

Yes, there are ways to keep the ads displayed on the screen even when the user scrolls down the page. There are various ways to do this for example the use of divs or javascript. As with everything though there can be downsides. Remember of course that although you are only allowed 3 regular ads, you are also allowed an Adlinks ad in addition to these.

Another easier to implement solution is to put one ad at the top of the page, one at the bottom and one in the middle - that way wherever there are (unless it is an extremely long page) they won't miss them.

Sites that use JavaScript to make the ads follow you around everywhere you go remind me of being chased through the house by a mosquito.

There isn't a single site I've seen that does this that I've considered to be worth visiting.

In terms of Web design, this is one of the most annoying things you can do.

How desperate do you want to look?

p/g