I like this a lot. I thought about doing something similar for used cell phones, where you could find price discrepancies between Craigslist, eBay, Amazon, and some others.
I flipping love Trello and think this Boards App Store is fantastic. As far as board ideas, how about a Business Model Canvas, MVP, and some kind of a branstorming/comparing/sorting board, you know, for the "Ideas" board? Keep it up!
Thanks for all of the feedback everyone... it has been very exciting to actually "launch" something and get some feedback. You guys did a swell job of uncovering some bugs and edge cases. I'm going to keep pushing and at least get it working as advertised.
I did some research ahead of time and did come across purl.org, but had no idea about WebCite and a couple of the others. Yes, my project is basically the same as those.
Does this work as a single point of failure company? Who knows, but it's been fun.
It's pretty quick and dirty... purl.ly links will detect a 404 at the destination and redirect you to the google cache instead. Works great if that page is in the google cache, but it may not be.
I'll get around to caching the full content of the destinations at time of purl.ly creation next, and serve that if google is missing it.