It depends on the audience you want to reach. If you’re trying to reach a global audience, I recommend you shell out the cash for a choice placement in the most popular search engines. You can take a chance on free submission but it takes a while for the big guns to get around to your submission. I submitted a website to both Yahoo! and Google a month ago and I’m not listed yet.

Link Exchanges are fast becoming a good way to advertise. Google AdWords is pretty affordable. Print media is a great way to advertise too. Television in my opinion is becoming a bit too saturated with web ads. I don’t see that trend lasting very long even with the advent of web television.

In my experience I find that the best way to advertise locally is branding. Put your website logo, slogan and link on cups, t-shirts, bumper stickers, etc. and just give them away.

If you know your target audience, then get on message boards, chat rooms, and newsgroups related to that audience and tactfully hawk your site. I especially recommend message boards because they have a large captive audience and the adminstrator of the site will be more than willing to get an ad up for you at a reasonable rate.