Merlinxx - circa £20K to £25K is about right for the UK.
blue monday - depends on the operator and how little they can get away with paying you. I've seen salaries as low as £14K for a ops controller at a largish operator and anything upto around £25K - anything above is supervisor/management.
Before I left the crazy world of crewing - was on around £16k a year (or just over £1K a month take home pay) as a crewing officer, which went upto circa £19K as a supervisor. Ops controllers at the time were earning circa £19K - believe they are now on around £22K.
Once outside aviation, its scary how far behind the industry appears to be in terms of salaries. At my new employer, a secretary's starting salary is £25K a year, with 36 days leave a year. I'm on around £30K gross (£1840 per month take home) doing a job that paid £23K in the aviation business.