Jobster works best for people with network. Lot of times you might not simply know anyone in your dream company because the company is in another city or if you are new to the place etc. So you might not go anywhere with Jobster. Instead I like the jobs section on www.joelonsoftware.com site.

People visiting sites like joelonsoftware.com are usually those who like to keep themselves up-to-date with the latest in software field and also those like to listen to what the peers/ industry leaders have to say. I believe this itself is one of traits of a good programmer so the employers are advertising their openings with a potentially good programmer base. Perhaps Rober Scoble or Chris Sells should also start a job section at their sites :)