This is THE social networking site for business and careers. The beauty of LinkedIn is how it takes the old adage of “it’s all about who you know” and organizes your classmates and former colleagues into an easily accessible network. It’s these connections that can quickly offer insight into job openings and compatible companies while helping you get your foot in the door of your dream job. On top of that, LinkedIn provides you a list of job openings in your industry and city based on your profile.
http://www.linkedin.com/

Never underestimate the power of CraigsList. No, it’s not the latest media darling of the social networking world, but it continues to do a phenomenal job of connecting jobs and job-seekers in the industry and city you want.
http://www.craigslist.org

http://www.krop.com/

http://talentegg.ca

This is more purely a job search engine that pulls from all over the Internet. Social networking isn’t necessarily the driving force here, but it does provide networking tools within most companies that turn up in your search results using LinkedIn, Vault and Spoke. Beyond that, it offers some really useful city-specific info like strongest local industries, popular jobs, trends and the area’s financial landscape.
http://www.simplyhired.com/

If you’re looking to make a difference in the world, this is the site for you. Beyond job postings in the nonprofit field, Idealist.org allows you to create and join groups to find little pockets of friends that share your passions and experience, subscribe to blogs and RSS feeds on the info you want, and also find volunteer opportunities, organizations, events and even more great job sites in the philanthropic world.
http://www.idealist.org/

jobs on twitter (via followers) or on twitterjobsearch
http://www.twitterjobsearch.com/

http://www.mattclassifieds.com