Vicky,
Whilst I cant offer you any specific advise, I would suggest a call to a few IT agencies and ask the question (google "Computer contractor agencies"). I know you may not want to get a job through or with an agency, but they will have an idea of what skills are in demand, and can point you in the right direction.
Another source of information may be:
http://www.itjobswatch.co.uk/
This web site breaks down the number of jobs listed (split by Perm and Contract/freelance) by skill over a period of time.
There is no point in sticking with a skill if nobody needs it, but at the same, no point in learning a skill which is either going out of date or nobody needs.
As I say, speak to an agent, they will be able to advise you.
Good Luck
Jaffa