- SimplyHired - easy to use job search
- HotJobs - Yahoo's job site
- Monster - you've probably heard of Monster
- Indeed - newer site that allows you to filter by salary (for instance, here is an example salary search on computer science and data mining)
- LinkedIn - use your social network to find your next job
- erecruiting - for new college graduates
An interesting approach to finding your next job might be to leverage your social connections to match you with a good employer with needs inline with your skills. Of course, as nice that sounds in theory, I would bet it could be challenging in practice.
Although, I won't be needing a full-time job for another couple years, it is always interesting to see what jobs are available (and what skills are in demand) by quickly searching on your skills and interests.