Have you ever taken a 5-in-1 collapsible reflector to a shoot on a windy day? Did you feel that you were paragliding? While I am a big 5-in-1 reflector fan, one cannot ignore the wind traction factor these carry. They offer great light in exchange though.
The folks over at Neumann Films have a great tutorial on building a set of sturdy, Particle Board based reflectors that: A – do not take off in the wind that easily and B – can be attached to a tripod/lightstand and do not require a dedicated person to hold them.
The idea is to use a particle board pieced from home depot for about $20 with some reflective film, and glue the two together. The result is a heavier flat reflector. It takes a bit more manpower to get them to location, but once there, they need little attendance.