If you need a squat rack, by far the fastest and least expensive way to make one is simply to sink 2 4x4's in the ground, anchored with concrete, and bolt 2 L-brackets (bent upwards to 35 degrees) to them. You can add a second set of brackets lower so it can double as a rack for bench presses (just add a sturdy bench, which is also easy to make).
And if you make it tall enough (get 8 to 10 ft posts) and make it sturdy, you can also use it for chin-ups. Essentially, these two posts, 6 l-brackets and 2 metal bars can be a bench press, squat rack and chin-up bar to do chest, back and legs. The only downside is, it's outside.
You could make an indoor version but it would take up a fair amount of space and require a different base. For indoor use a box rack system like this one (see the box at right), but made of 4 x 4's world work. The commercial racks cost between $300 and $600 (and up). A homemade indoor version, made of 4x4's L-brackets and bolts would likely cost less than $100
Click on each link for additional photos and information. (coming tomorrow)