I had a reasonably new front wheel on my mtb that taco'd when it grabbed suddenly on a corner. I waffled for a few months, riding my road bike in the meantime, about getting a new rim, and new spokes that I'd had my eyes on. In the end, I went with an old, never built rim hanging in my garage. I checked that the diameters are the same and taped the rims together. Then I just unscrewed all the spokes and nipples from one rim and moved them over to the other. It took about an hour. The bike has disc brakes and the rim has brake sidewalls, but that doesn't make it unsuitable for the application, it just looks a bit funny.
I would only recommend this if the spokes don't have too many miles on them and the rims are the same diameter at the spoke holes (ERD), but otherwise this is a great/fairly easy way to get a new wheel for less money. I've got 3 more of these rims hanging in the garage (got them on close out), so I'm good for a few more years. The best part is that they are 700C (29er in mtb parlance), so I can use them on my road, cross, and mtb bikes (yes I have too many).
