Apple’s Reminders app lets you create location-based reminders, but the process seems backwards to me. The only way to create a reminder for a specific location is to be in that location or to type in its actual address. It’s prohibitively clunky, but there’s a solution.
Localscope for iPhone is one of my favorite location-based apps. It lets you view your surroundings or any location through a whole bunch of lenses like Yelp, Flickr, Wikipedia, Foursquare, Twitter, YouTube, Instagram, Factual, and more. It also works with TomTom, MotionX, and quite a few navigation apps so you can get there your own way.
When you view the details for any location in any service, one of your options is to “Add Reminder”. You can enter a title, pick a Reminders list to use, and—here’s the key—choose whether to get a reminder when you enter or leave that location. Plus, Localscope adds a link for that location to the notes section of your reminder, based on the service you used to find it. If it was Flickr, it’ll be a Flickr URL, or Yelp will get a Yelp URL, and so on.
It’s a great way to get reminded about a place you want to check out when you happen to be near it. Besides, what have you got to lose? Localscope is free in the App Store, and some services get enabled with a well-worth-it in-app purchase.