Weaving - which loom to have?

[JG]

Sorry if this has already been covered, but does anyone have information to share on weaving? I'm approaching a special birthday, and, as a knitter, am attracted to the thought of weaving with a variety of yarns, or maybe evne more adventurous thread. I'm aware that there is a simple version of a lomm called a knitter's loom, or table loom, which is quicker and easier to thread up and will create various fabrics, depending on the maximum width of the loom. Has anyone out there had a go with one of these? If so, should I go for the largest I can afford, or will this be too daunting or unwieldy for a beginner?
I've also seen, in a rather hippy handicraft book, an idea for making a loom out of cardboard, for one project at a time.