I just saw ads on my site where the Adsense block is an accordion.
A 336x280 text block contains four headings, hovering on one opens that section and closes the others. On load the top tab is open.
I quite like the format: interactive without being annoying. Increases number of ads without using more space.
If only Google could improve their targeting...
I have not used Adsense for months and only just put it back. Is it completely new, or something that has come out while I was not paying attention?