I’ll stick with the static images for ads.  I’ve seen animated gifs that do exactly what one of the above does.  As for flash, I installed flashblocker a long time ago.

I had sent Macromedia a suggestion years ago that they offer the user an option of seeing the flash animation or a static image that would launch the animation; this way, if the user selected the non-animated default, they would at least see some image indicating what the flash animation was about.  Now, if the user has a flash blocker installed, they just get the “f” and might have no idea what lurks behind it.  Since they ignored it, their users now effectively get a blank area and the advertiser gets no visibility.

Rules I have for advertising:

  1. Don’t make it obnoxious.
  2. If you use an animated image, make sure the first and last frames are meaningful by themselves; this handles the no  and run-once animation cases.
  3. Don’t use Flash.  Actually, don’t even use it on the main page on your website or any other page unless it really serves a useful function.  See rule 1.