Just got the new Lee Valley catalog. Couldn't help but notice their offering of neat little, portable dollies. They are made of polypropylene, they are built on platforms 10 1/4" by 10 1/4". They can be locked together to make larger platforms. Each 10 by 10 dolly has 4 swiveling wheels 1 1/2" high. One square will support 80 lbs. They are sold in Pairs and priced/ pair.Looks like what I have been looking for to use on "almost completed" projects to wheel them into a corner, while working on another part. They could also be used for support under rolling cabinets/benches. Or to make a rolling cabinet out of an existing one without wheels.
The price is attractive enough for me to make this post. Until Oct. 15, '07 a pair of 10 by 10 casters cost $9.95 US (10.95 Canada). If you buy 3 or more pairs, the cost is $8.95/pair US ($9.85 Canada).
The site is http://www.leevalley.com The Catalog No./Item No. is 88K17.60