Statistically speaking you are here because you googled the phrase "tube map" and came up with my page. The image in question is actually hosted by a site called londontown.com and the image can be found HERE.
Yesterday I was made redundant from my job, working at a London University as a Travel Plan coordinator. The irony that most of my blogger traffic has been from people seeking travel advice is not lost on me, so let me give you the following useful London links:
Walkit - a website to help you plan walking routes in the city - why take the bus or tube when you could just walk?
TfL - obviously the Transport for London site is the first port of call for travellers - THIS page will give you access to the most useful bus maps, and below is a journey planner from TfL
I hope this helps you find your way round London a bit better, and please feel free to stay and read more from this blog than just where the met line runs (Uxbridge / Amersham / Watford to Aldgate by the way)