The software you’d be running would look like an Instant Messenger application — it would show a buddy list of people that are within 100 feet of you. This software connects to others’ wifi cards, kind of P2P-ish, so that you can “know” who is within 100 feet range of you (100 feet is the typical distance for wifi 802.11b/g cards in laptops). This software then shares information on the people that you’re connected to, with everyone that is connected to you — thus, I might see “User1″ and User1 is connected to User400 (but not me) — so User400 might appear in my buddy list, but as a “second degree” (~200 ft) physical contact. You could then find someone to randomly chat with or play a game with – “you’ve received an invite from Margot7448 to play chess”.
Benefit: This could get you to meet new people — rather than just having virtual friends and relationships, you could meet someone in person right then. Imagine if you were a single male and interested in meeting other single females — you’d see your buddy list, could browse the profiles of people you’re near (what are their interests?), and then… text chat with one instantly — see if there are some sparks, and then chat in person. Obviously, there would need to be security measures — because this potentially opens a can of worms for stalkers, pedophiles, and other criminals.
Users would have privacy controls — you could choose not to broadcast yourself on the network at the time; or have yourself hidden from specific users; have your profile hidden (allowing only your friends to view your full profile), etc.
Who: I think college students and high-density apartment communities would make this software truly explode — they could learn who else is in/near their apartment building; so you’d get to learn who your neighbors are and whether there are any similar interests. No one knows their neighbors anymore — well, most — wouldn’t it be great to learn who your neighbors are? And imagine you being able to broadcast items you have for sale or wanted — thus if you do live in an apartment community, you could search the ‘for sale’ or ‘wanted’ listings of people around your vicinity.
Some Technical Details: Basically, you’d have a profile on this new social networking service. You’d install a piece of software — on your Windows PC, it’d reside in your system tray. If you have a wifi card, this software would create a second “virtual” wifi card — thus, your PC would think it has 2 wifi cards. This new virtual wifi card would broadcast yourself and sniff out others near you (that your PC can “see” via them broadcasting themselves). Typically your wifi card can only connect to other networks within roughly 100 feet of you — so you’d be seeing those that are 100 feet from you (and then those that are connected to the people you’re directly connected to).