Despite some predictions otherwise, the rise of social networking hasn’t pushed email and instant messaging into obscurity just yet says a report by The Nielsen Company.

Although both saw double-digit declines in share of time, email remains as the third heaviest activity online (8.3 percent share of time) while instant messaging is fifth, accounting for four percent of Americans online time.

The way U.S. consumers spend their Internet time on their mobile phones paints a slightly different picture to that of Internet use from computers. In a Nielsen survey of mobile web users, there is a double-digit (28 percent) rise in the prevalence of social networking behavior, but the dominance of email activity on mobile devices continue with an increase from 37.4 percent to 41.6 percent of U.S. mobile Internet time.

Americans spend nearly a quarter of their time online on social networking sites and blogs, up from 15.8 percent just a year ago (43 percent increase) according to new research released today from The Nielsen Company. Though the company did not give a breakup of the social networking sites, but considering the popularity of Facebook it is apparent where you spend most of your time.

The research revealed that Americans spend a third their online time (36 percent) communicating and networking across social networks, blogs, personal email and instant messaging.

Online games overtook personal email to become the second most heavily used activity behind social networks – accounting for 10 percent of all U.S. Internet time. Email dropped from 11.5 percent of time to 8.3 percent. Of the most heavily-used sectors, videos/movies was the only other to experience a significant growth in share of U.S. activity online.

Its share of activity grew relatively by 12 percent from 3.5 to 3.9 percent. June 2010 was a major milestone for U.S. online video as the number of videos streamed passed the 10 billion mark. The average American consumer streaming online video spent 3 hours 15 minutes doing so during the month.

Portals remain as the second heaviest activity on mobile Internet (11.6 percent share of time), despite their double digit decline and social networking’s rise to account for 10.5 percent share means the gap is much smaller than a year ago (14.3 percent vs. 8.3 percent).

Other mobile Internet activities seeing significant growth include music and video/movies, both seeing 20 percent plus increases in share of activity year over year. As these destinations gain share, it’s at the cost of other content consumption – both news/current events and sports destinations saw more than a 20 percent drop in share of U.S. mobile Internet time.

“Although we see similar characteristics amongst pc and mobile internet use, the way their activity is allocated is still pretty contrasting, added Martin. While convergence will continue, the unique characteristics of computers and mobiles, both in their features and when and where they are used mean that mobile Internet behavior mirroring its PC counterpart is still some way off.”

1. Facebook
2. Amazon
3. Apple
4. Google
5. Huawei
6. First Solar
7. PG&E
8. Novartis
9. Walmart
10. HP
11. Hulu
12. Netflix
13. Nike
14. Intel
15. Spotify
16. BYD
17. Cisco Systems
18. IBM
19. GE
20. Disney
21. Gilt Groupe
22. Indian Premier League
23. PatientsLikeMe
24. Grey New York
25. BMW DesignworksUSA
26. Synthetic Genomics
27. FiLife
28. Frito-Lay
29. Alibaba
30. MITRE
31. HTC
32. Diller Scofidio + Renfro
33. Firstborn
34. Sportvision
35. Ideo
36. Samsung
37. Glam Media
38. Ngmoco
39. VNL
40. Aldi Süd
41. Fast Retailing
42.Huayi Brothers
43. Athenahealth
44. MVRDV
45. Alstom
46. Quantcast
47. Good Guide
48. Microsoft
49. Politico
50. Twitter