I HIGHLY recommend shutter release cables (
30D is here). I have the same one, works well, I cut the cord in half, and put in 1/8" stereo plugs (male on one side, female on the other) so if I want I can extend it with a headphone extension cable, or trigger it with something like a pocket wizard. Unfortunately, this is one accessory where paying the $50 for the Canon version is worth it, as the generics can be pretty cheesy and break quickly.
As for the image, looking good! I would echo everything PM said, but also throw in that I might like to see it taken a bit earlier in the evening so the sky isn't so dark, but I like how the neon is looking.