iSepta, a new iPhone friendly site, has a limited audience, but to that audience (of which I am a member) it's a game changer. As I've mentioned once or twice here on TUAW, I'm a proud Philadelphia resident. As such I find myself using public transportation fairly frequently, which means I am forced to use SEPTA's website (that's the Southeastern Pennsylvania Transportation Authority, to you).
Starting a new trip with iSepta couldn't be easier: Click the 'New Trip' button, enter your starting station, then select your destination station.
SEPTA runs, amongst other things, the Regional Rail, which connects Philadelphia to its suburbs with a series of train lines. iSepta lets you plan your trip from the comfort of your iPhone without having to visit the official SEPTA site, which is decidedly mobile-device unfriendly.
That's it. You're then presented with the next 5 trains that meet your criteria, as well as an option to view the weekday and weekend schedules. iSepta is even clever enough to simply swap your starting point and destination so you can quickly find out what time you need to be at the station to get back.
You can also text iSepta with your starting point and end point and it will text you back with the next 3 trains.
At the moment iSepta only offers up schedules for the Regional Rail, so users of Philadelphia's various other forms of public transportation are out of luck. The site also lacks SEPTA's up to the minute status about cancelled trains and late arrivals, but the developers are working on adding that.
If it seems like I'm gushing here, that's because I am. iSepta is such a vast improvement over SEPTA's website that I'll be using to get all the info I need about the Regional Rail schedule whether I'm on my iPhone or at my Mac.