[Does anyone knows where this mesh head is from?]

That's a head from The Mesh Project. Fair warning though, to wear the head you need to have the body. 

 

Webpage:  http://themeshproject.org

Slurl:  http://maps.secondlife.com/secondlife/The%20Shops/128/128/4

Review of body:  http://meshbodyaddicts.com/mesh-body-reviews/mens-bodies/tmp-mens-body/

 

 

 

 

[So what do you guys do in SL?]

Ha! You sound like me, I'm a chronic lurker and part time creeper. I always feel a bit lost once the shopping buzz wears off, but I mostly explore and try not to look too awkwardly out of place.