Also, next time you get a job, try to get it in a small company (max. 50-100 people), because those are the companies that really need to be on top of their game in order to make a profit, so you'll be learning a lot of new stuff there.
Here's a couple of websites to get you started on your job hunt:
http://startuply.com/ - startups
http://careers.stackoverflow.com/ - I actually did a search on london and quite a few companies popped up
http://jobs.github.com/positions
I follow the London craigslist and that one has some open start-up positions every now and then
And also there is www.monster.com, but the postings there are not usually startups.
I wish you good luck. If you make it big in a start-up, let us know how you did it.
-Justin www.wyckwyre.com