When Cyclopath came onto the scene I thought it was a great leap forward for cycling route-finding. This tool was developed by Group Lens Research, a "human-computer interaction and social computing" research group at the University of Minnesota.
If you are not familiar with Cyclopath, it's a WIKI based knowledge aggregator - bicyclists can rate sections of road for cycling suitability, enter landmark data like coffee shops, bike shops, etc. and generally contribute to the body of knowledge in the Cyclopath database. Because it's always updating, it could even be used to keep current on temporary route problems such as trail closures or ice roads (assuming we all keep it up to date, that is). Like Google Maps, Cyclopath will let you find a route as well, but what's more, you can weight the results by ranking bikeability, speed, distance, etc. as you prefer, so it's really a pretty amazing tool.
In the early development of Cyclopath, I and many other Twin Cities cyclists contributed information to the WIKI to get better and more complete information into the WIKI. I still contribute data when something new comes up, and I use it if I have to find a route to or from some place I have never ridden before. I have had really good luck with it and appreciate the service (in fact, I stuck a link to Cyclopath on the right side of this page as testimony to this endorsement months and months ago).
AND IN THE OTHER CORNER WEARING THE WHITE TRUNKS...
Google Maps was petitioned to developed a "Bike There" option for it's route-finding tool by many, many cyclists. I think I signed some electronic petition to that effect last year, as a matter of fact. On March 10, Google, um... uncovered their tool with great fanfare.
Today Cyclopath published a pretty persuasive counter-offensive treatise on why it's superior to the Google Maps tool. Cyclopath points out, for instance, that Google Maps has some errors, like omitting the Sabo Bridge and LRT trail and makes mistakes like routing cyclists onto the Hiawatha Ave. - I-94 interchange(!).
I have not fooled around with the Google Maps tool much, but I am very confident that Cyclopath is superior to Google Maps. That said, I am concerned that this could become yet another Wal*Mart-like tragedy where a massive corporation uses its scale and capital to strangle a smaller, higher quality competitors, and we all end up with some inferior product in the deal.