A couple of months ago, waaay before the investment opportunity even came up, I was interviewed by Eze over at VC Cafe. His last question was "What are 5 sites you can't do without?", and HopStop was on my short list. HopStop is my car replacement in the past couple of years. I use it on average 3-4 times per day and cannot imagine how I got around the city without it. If you live in NY, or plan to come for a visit, you should absolutely head over to HopStop and start planning your public commutes from place to place. (BTW - if you're even considering using Google Transit, take my word on this one - HopStop is 10x better and much more accurate and useful).
HopStop has done a great job of building a wonderful service on a shoestring. It has been integrated on sites like TimeOut, Corcoran, and Halstead. Now were looking to add many more partners to use HopStop for powering their "How to get here?" directions/mapping pages. HopStop's free API is available here for any site to embed. If you are a local site in one of these metro areas - NY/NJ, San Francisco, Washington DC, Boston or Chicago - HopStop is the *best* directions service for your users, and it is absolutely free for you.
I can go on and on about how much I like the site, but I'm not objective... head over to NBC's local NY channel to watch a great item about HopStop from a couple of days ago.