There is a strategy called "link baiting" which is basically all about trying to put something interesting on your site that people will link to naturally. Matt Cutts defines link bait as anything "interesting enough to catch people's attention". It might also attract interest on the Social Network in sites like del.icio.us which can give your site a big traffic boost. Furthermore it's quite likely to increase return visits to your site if you've got something interesting on it.

I'm looking at my list of favourites and they are all sites that are giving something away for free - SEO tools mostly in my case, or quizzes - or freeware downloads.

Have a think about your industry - are their any tools that you use frequently that you can give away - a spreadsheet with calculations built it - or maybe you've got some coding knowledge and can code the tools up into web pages.

Offices like quizzes - it gives colleagues a chance to thrash each other - there are lots of freeware scripts on the internet - I've just used one to create an SEO Quiz - see what score you get :)