dan,
I am (unfortunately) well acquainted with shin splints, so can perhaps pass on some advice, and hopefully they'll heal quicker for you then they have for me.
I have had shin splints twice (I'm 22 BTW). First time was a few years ago, and I went to a physio. However, I never got back into running after the treatment, so I don't know if it really worked or not.
I started running again in August 2002, and in October started getting shin pain. I knew this was splints, so went to a physio. I have been having treatment of some form since then! In fact it's only been this past week that I've been able to run for any length of time without experiencing pain, so that's nearly five months of having the wretched things.
Remember that they can be beaten (you can lose sight of this if you spend a long time injured). It may take some time, but you shouldn't let them stop you from achieving your goals.
Professional opinion is not consistent on the causes of shin splints. A podatrist may tell you it's related to foot pronation whilst a phsyio may tell you it's either muscle strength in the legs, or flexibility of those muscles. Both of them will tell you not to run so much on hard surfaces.
Because of there being varying professional opinions on the cause of shin pain, I took the approach that they were all correct, which meant that I went to two physios AND a podatrist and followed the advice that they all gave me. This meant:
1) Stretch everyday. In fact, twice a day. All the muscles in your legs.
2) Perform strengthing exercises for the lower leg muscles (start with toe raises).
3) Use orthotics (I am a hyper-pronator, so have some inserts that help correct this)
My advice would be (if you are currently suffering), go to a good physiotherapist who can make an assessment of what the actual problem is. "Shin splints" is usually a catch-all term for lower leg pain; medial tibial stress syndrome (MTSS) is pain on the inside of the tibia, anterior shin splints is pain on the outside of the leg, and compartment syndrome is not even really "shin splints", but is certainly something to be considered when diagnosing shin pain. MTSS is the most common form of shin splints, but as I say, go to a physio and get a proper diagnosis.
They will be able to treat the leg with a variety of techniques, as well as tell you what to do to help prevent a recurrence.
As well as the physio, go and see a podiatrist (I would advise that anyone who does a lot of running actually go see one). I went to see one who was recommended to me, and he has done a great job. He did a full video analysis of my gait, as well as a check on my lower leg muscle stength. He provided some custom moulded insoles that have helped correct my running style, so that I no longer get any pain (touch wood

).
A good article which emphasises the fact that there is no single cure for these things, can be found at the following link:
http://svr-www.eng.cam.ac.uk/~kmk/shin_splint.html
... but by far and away the best resource EVER is the following link:
http://www.sportsinjurybulletin.com/arc ... atment.htm
I follow all the exercises recommended in the above, and it's worked for me. If you want anymore links, post on here and I'll check my bookmars at home and post them up.
Best of luck,
Joe