Whats the average salary?

Its based on US jobs but still a very useful tool for comparing salaries and skills.
http://www.indeed.com/salary

You can even add 2 or more skills/job titles to compare the salaries

http://www.indeed.com/salary?q1=java&l1=&q2=php&l2=&tm=1

java $95,000
php $81,000

View Larger Salary Graph

And of course in Google you can simply type 80000 dollars in pounds
http://www.google.co.uk/search?sourceid=chrome&ie=UTF-8&q=81000+dollars+in+pounds


There's also a trend tool to see if your job or skills are in demand
http://www.indeed.com/jobtrends?q=java%2C+php&l=

java, php Job Trends

Java jobs - PHP jobs