Most popular keywords have become quite expensive at Overture (the first and biggest engine) and are rising at the others. "Google adwords" is a good alternative. Any suggestion ?

Here are some PPC search engines:

http://www.enhance.com - (formerly ah-ha.com) was founded in 1999 as a
family-friendly search engine and has now branched out to offer paid listings, paid inclusion, banners and other contextual ads.

http://www.goclick.com - another good PPC search engine.

http://www.kanoodle.com - Kanoodle has partnerships with sites such as, NetZero, DogPile, CNET, Metacrawler and Turbofind.

BrainFox has a minimum bid of only $0.001 or one tenth of one cent. You can also start an account with BrainFox for as little as $5. Worth try http://www.brainfox.com/

Arrrh....But does anyone really use pay per click search engines? They are just darn annoying.

pay per click doesn't work, it's just a waste of money

I have to agree with Trojan. It's just so annoying. I hate it! Its what makes the internet bad.

Yep. Google Adsense is great for people who want to get traffic and people who want to make money.

yep google adwords is great for advertisers. i have used them before. great traffic.