Hi

I'm building a site and have allowed room for some 468x60 banners. I'd like to use something bigger but the only "official" bigger standard is the huge leaderboard size of 728x90 which is far too large for me to squeeze in.

I was wondering whether I could make my own banner size of say 600x120, would I get laughed at if I went to potential advertisers and said I needed their artwork in 600x120?

Anybody else break free from the 468 or 728 options?

Thanks for your time!