I carry different permutations of gear for different assignments. This is my single person portrait kit. If I know I'm shooting just one person this is all I'll bring. Basically, the camera, a wide lens (17-55), a portrait lens (85mm), some light to give me more control (Nikon SB-800, SB-28 with pocket wizards), some light stands and an umbrella or softbox.
With this setup, I can shoot a nice available light portrait outside in the shade. A dramatic portrait where I over power the sun with a little help from the Nikon speedlights. Or I can also shoot inside and get a nice studio-ish portrait with the umbrella or softbox.
All this fits in my Xtracycle. Brilliant. I don't accelerate or climb hills as fast, but I can still move at a good clip (cruising around 18mph). Which means, I can get from my apt to City Hall in about 12 minutes, or to Belmont shore in about 15 minutes and seal beach in about 25 minutes.
This particular setup I took to shoot the Garden of Eva portrait (see the entries below) which is at the border of Long Beach and Paramount. It took me about 35-40 minutes via the Los Angeles River bike trail.