LinkedIn is one of the most underrated social networking sites on the planet. Until recently, the service was not getting too much respect from Web 2.0 fanatics. But as Facebook and Twitter have become more mature, people have come to realize the need for a more formal community to find jobs and network with others in your niche. LinkedIn comes with a whole lot of tools that anyone can use to expand her network and take her career to the next level.

But there is more to LinkedIn than meets the eye. There are a whole lot of things you can do on LinkedIn to expand your network, build business, and develop new products. What you don’t want to do is spam people and insult them. But don’t be afraid to ask for favors and reach out to superstars.

Here are things you can do with LinkedIn:

1. Build your network
2. Connect with your friends on LinkedIn
3. Get the latest news in your niche.
4. Reach out to professionals in any niche
5. Build a Group.
6. Publish your blogs on LinkedIn
7. Promote your business
8. Promote your blogs/websites on your profile
9. Find clients for your consulting business.
10. Track industry experts
11. Ask questions!
12. Establish yourself as an expert by answering questions.
13. Tell others what you are doing now (status)
14. Better yet, tell the community what you need.
15. Do market research.
16. Do company research.
17. Come up with new product ideas from Q&A and Groups.
18. Share your slides on LinkedIn.
19. Connect with your colleagues face to face.
20. Collaborate privately with your colleagues.
21. Track polls.
22. Better yet, set up polls for the community to respond to.
23. See what others are reading and share your reading list.
24. Track your business’ online reputation.
25. Recommend others and get recommendations.
26. Find events online.
27. Hire employees.
28. Get job offers.
29. Track your progress in the community.
30. Manage your contacts.
31. Ask for product feedback.
32. Observe what others are doing and innovate.
33. Write an app for LinkedIn.
34. Advertise on LinkedIn
35. Push your Facebook groups/profiles
36. Push your Twitter account on LinkedIn
37. Offer free service and get more clients.
38. Share free reports and go viral.
39. Push a great cause.
40. Manage your contacts from Outlook.
41. Answer to famous people’s questions.
42. Start a business page.
43. Manage your LinkedIn account from your browser.
44. Learn about new job search tactics.
45. Buy Job Credit
46. Create and track surveys
47. Upgrade your account and reach more users.
48. Send direct messages to top folks in your industry
49. Ask for interviews on Linkedin
50. Find Guest bloggers.

There are a million other things you can do with LinkedIn. As long as you are not stalking, insulting, or spamming, you should be fine.

Your take: how do you use LinkedIn?