Here is some high pr dofollow sites wgere you can build profile Backlinks:
1. Technorati
2. Blogger
3. LiveJournal
4. Youtube
5. Vox
6. party.com
7. Acrobat Users
8. Hi5
9. Blurb
10. Squidoo
11. Viddler
12. Kirtsy
13. HubPages
14. Naymz
15. Twellow
16. Gather
17. Aviary
18. Spoke
19. Anobii
20. Design Float
21. Knownem
22. Amplify
23. Blippr
24. Active Rain
25. Bizsugar
26. Agency Scoop
27. Blog Interact