'barefoot' style shoes

People who use these, do you use them all the time or only on particular surfaces? Do you do some runs in heavier shoes (and if so, why?). What have been the advantages to you of using them? And (silly question coming up), are you meant to wear them barefoot i.e. no socks? I like my current running shoes and they are much lighter than trainers, but I wouldn't mind something lighter weight to run in. Someone mentioned merell gloves on another thread and I like merrel's normal trainers as they tend to fit me very well, so thought I might try some, but to be honest I don't really know that much about it.

i found them benneficial, not everyone does, i'm faster, better "form" feel better durin and after runs.
I dont wear socks very often with them, unless its cold or if i'm planning a very long run, just in case.
Trailgloves are quite snug, i would go try them on, dont buy blind if you havent worn them before, but if you cant, go at least a half size up.  

Is it true all this stuff about having to build up running in them really gradually? And can you just do other runs in 'normal' running shoes at the same time? I've only been able to do 5k since the start of the year, and just hit 6k. I would be loathe to take steps backwards at this point, but equally I'm just not sure how much I believe that it has to be done so slowly. I mean, I would imagine that I could run (on a decent surface) as far barefoot as I can in shoes. But perhaps I am wrong?

The barefoot experience is different for everyone I think, I moved into Vibrams about a year ago and my first run was 18km, I then went out the next day and did a fast trail 5k but my calves ached from running in a different style. It took about three weeks for me to transition properly and I stayed in my VFF Komodo almost daily for six months across all types of terrain and wearing socks or not, if you wear socks in barefoots I think you can't beat the Injinji ones.

However, I do also wear other trainers too, I run Adidas Adios, Saucony ProGrid Jazz and a pair of old Asics Tather which a quite waterproof. But I found that I need, having had the experience of lightweight runners, something minimal. I'm currently using as my general running shoes (up to ultra distance) Newton Distance, Vibram FiveFingers Komodo and Merrell Trail Glove and this is a great selection for me. But it's not for everyone and each minimal pair of shoes is different. The Vibram Speed for example ruined my feet for a few months as they kept blistering them and causing all sorts of aching - but that was one shoe.

I would say if you fancy slightly more minimal wear then just try them, some people know instantly that they are what they have always been looking for, some people think its just plain weird. Good luck!

i think its worth going into barefoot slowly, a lot of people dont and get injured, i'd ran many miles in a very low drop minimal shoe when i switched and my calfs and achilles screamed at me the next day. and i'd even been walking in Vibram Five fingers for a few years. 
i would suggest you keep on your normal shoes for the long runs you built up to and on the days off go for a quick mile or so in your minimal shoes, maybe run round a field/football pitch/park on the grass especially if you're a heel striker, you will soon find out in barefoot shoes believe me.

this is a pretty good guide on transitioning. 

http://www.merrell.com/US/en/BarefootConnection 

take moving into minimalist shoes slowly it will be worth it in the end. I made the change 9 months ago and i feel far better than when  i ran in shoes. I run in luna sandals and vibram bilikas i find both are great. I wear injinji socks with both, great socks that wear well and dont cost the earth. I wear my vibrams and luna's all the time for running, tarmac and trail.