For the truly desperate, a handful of apps can alert you to locations where you might score a date. The lamely named Where the Ladies At app for the iPhone uses Foursquare's APIs to determine exactly where the most "ladies" are concentrated. Similar apps can help you track down other demographics of people, but I'll let you discover those on your own.
Video Chatting and Other Apps
For those with spouses or partners traveling or working overseas, the next best thing to actually having them around is video chatting with them. And now, you don't have to be tied down to your PC to get some face-to-face action with your loved one. Most of today's high-end smartphones, such as the iPhone 4 or EVO 4G, have front-facing cameras and come preloaded with video-chatting software like Skype or Yahoo Messenger.
Other apps may not be intended for romantic purposes, but can still be used as such. For example, apps that let you share grocery lists--like Grocery Gadget--are also a means to slip a cute "Love ya!" note in between "bread" and "lettuce."
And what is a more romantic way to ask somebody out than by sending them a Google Calendar invite for dinner at Chez Panisse at 8 PM? Or take it a step further and send your boyfriend or girlfriend a Calendar invite for "Our Wedding" next year, location TBA? Okay, maybe not.