Hand me a feedback about this:
What about a Flash banner that has 4 planets starting at every corner of it, then slowly move to the center of it leaving a trail of stardust and collide. At the collision event the movement stops and the writing 4Dimensions - Where worlds collide. Appears. Then disappears after 3seconds and the big transparent writing allowing viewing the tremendous graphic behind it says:
Click to collide(play)
You can't afford missing such experience
We can have also a still version of it in jpg format showing only the collision of the planets and the 4d name and slogan. Writing in the right-lower corner 'Click to Collide(play)'
The worlds mixed colors: Red, Blue, Gray, White
About the LOGO, I believe a simple 4D big writing with some welcoming colors would suffice since the square space is limited.
PS: I found over google a standard for banners with grephic examples of them instead of just the dimensions: http://www.simplygraphix.com/banners_sizes.html