I'm a fan of data projectors for gobos but noticed that cheaplights is now offering a 20-watt version that uses transparency paper. Still not sure how you'd overcome the density problem on transparencies but a 20-watt might actually be enough for a decent gobo. Anybody tried this or something similar with good results? If nothing else, it might make a good cake pinspot. At $129, it's a bargain.
http://www.cheaplights.com/cart/page14.html
http://www.cheaplights.com/cart/page14.html