The Met have launched an online crime map for London (what's a crime map?).
You can search it by postcode or by your Greater London borough to check the crime rate for your area (the bigger the number, the worse the crime rate), see if it's rising or falling, compare it with crime rates in other parts of your borough, and even see the trends in your area over the last 3 years.
If you want you can even find the detailed crime figures for your area (scroll to the bottom of that page to enter your postcode) - though there's a FAIL for not being able to find the area of my postal address for that particular search!
The detailed figures seem reasonably up to date, broken down into number of offences for burglary, criminal damage, drugs, fraud/forgery, the famed "other", robbery, sexual offences, theft and handling, and (other) violence against the person - if you really want to know. (A graph for those would have been helpful.)
Go check the London crime map for your area, and quiver (or cheer).
(Via the BBC - who report a similar crime map scheme in the West Midlands and say the government have promised crime maps for all of England & Wales by the end of 2008. What about Scotland or Northern Ireland?)