I just returned from a couple weeks in London. They've really got the right idea there. Here are a few things I saw that we could really use in the US.
1) Bike racks everywhere
2) Bikes can ride in bus lanes and there are many bike lanes
3) Public messages everywhere encouraging people to bike
4) $7/gallon gas
5) "Congestion charge" (i.e. a fee you have to pay just to drive downtown) -- $15/day. There's talk about upping the charge to almost $50/day for gas guzzling SUV's though they are not very popular thanks to the cost of gas
6) Friendly drivers that actually pay attention on the roads.
I wonder if the Londoners on BF know how good they have it.