I cant sit more than about 30 minutes before I start having the same problem, so I just get up and go away and come back later. I havent found anything that helps and sometimes if I have sat here too long, I go take a really HOT shower and apply some Ben Gay to my neck & shoulder.

Thats the beauty of a laptop. I can sit back on my couch with my neck resting and use the computer. I try to limit my time to one hour in the a.m. to catch up and then in the evening I do the same. I use an orthodic seat while on the couch as I have a bad back. Maybe you should look in to an ergonomic chair.

My work days are often over 10 hours at the computer.
You should make sure that you have an ergonomic work area. If you google "ergonomics" you will find sites that can give you very basic guidelines for Chair, monitor and keyboard heights. A good chair makes a world of difference.
Getting up and moving around every hour or two really helps me and I do some neck and shoulder stretching exercises.

Joann, do you have good lumbar support? Even if you think you do, try getting a small rectangular pillow and putting it at your lower back. Other than that, gardenspice said it all. Don't give up, keep working with it and you'll find something that works for you.

My problem is that my eyes become very tired.

If it's your neck and shoulders, check out the height of your monitor. If mine is too low or too high, it really gets me in the neck. My monitors at home are on a bracket that adjusts to my ideal height. The monitor at work is more of a problem, because the person who uses my desk during the day shift is 6" shorter than I.

Also, do you wear bifocals (or progressives)? If you tilt your head all the time to read what's on the screen, this will cause problems. I have a pair of single-prescription glasses just for computer use and piano playing.

I'm not on the computer as much as some of you but I do spend some time there.

I bought one of those mesh lumbar supports that slip over the back of the chair with elastic. It really helps. My computer chair has arms and height adjustment.

I use a track ball mouse so I don't have to be leaning over a mouse pad. My keyboard is wired but long enough that I can lean back and t rest it on my lap. Not confined to the desk.

I have a laptop and would be ashamed if I figured the time I spent on this thing, but I e-mail a lot of people, and come here and the MH and google books, etc. etc. Plus I play free cell and Sudoku and that blasted train game when it's free, Sometimes I use mine in bed, sometimes on the love seat in the bedroom, often the couch in the den. Even outside in a lawn chair. Just variety and move around occasionally.

I'm at the computer the entire day, as I work on it and browse the web often as well. I have no pain from it.

I'd check your ergonomics. Here's a link to an explanation of that so you can check it out.

Here is a link that might be useful: http://dohs.ors.od.nih.gov/ergo_computers.htm

When I used to spend all day at a PC, I used the tower as a foot rest.
Works.

Don't rest your arms or shoulders on ANYTHING. This pushes up on those muscles in your neck/shoulder area which creates pain. Hopefully you have your mouse lower than the monitor; if not, consider putting a flat surface on your lap and put the mouse/keyboard on that. I find this makes all the difference between pain and no pain.

If you work at a computer all day, you should get your eyesight checked at least once a year. Mine got worse every year I used that computer at work. We were told to take frequent stretch breaks and gaze away from the screen as much as possible. Also had an ergonomic chair with a footrest you curl your feet around.

I stared at computer monitors almost daily, for well over 30 years...and my eyesight is no worse.
And still wear progressive lenses - if the lenses are ground properly, they do no harm.

And the key to back comfort is to keep your feet raised, not flat on the floor. Any type of foot rest helps, at least 6" off the floor.

I am at a computer all day, usually by 7 or 7:30am till at least 5:30pm and often till 8 or so after a quick supper break. The chair is vital, spend what you need to in order to have comfort. This is my chair, I've used it for 3 years.

Here is a link that might be useful: My chair

Thanks everyone. I had a regular computer chair then got the ball, now I am sitting on a junky folding chair. I have the mesh screen thing, its not worth anything IMO. I will try it with my feet up and I will read that link.
I have this darn frozen shoulder and its hurting my left arm muscle if I sit long anywhere. It feels like someone is punching it. It just makes no sense to me. Next stop will be to acupuncture if things don't get better quick.