Completely unrelatedly, I'm experimenting with location-aware software. I'm trying to work out in which ways it can be useful or interesting.

I tried the obvious first, and got a restaurant recommendation service (Urbanspoon) which will take my location into consideration when helping me choose (or randomly choosing) a restaurant.

I've seen references to location-aware to do managers, and Astrid, which I use, has a paid plugin, but I don't know how sophisticated it is. The documentation is really sparse. I mean, will it tell me to get milk when I pass *any* grocery store, or just the one I said I get milk at? Or maybe any Ralph's? Not asking those questions specifically about Astrid, just location aware task managers on the market.

Somehow in this experimentation I turned on Google Latitude (I blame Ambien). Scary. But at least Google sends you an email when you turn it on, so you can then panic and turn it off. I don't know precisely what it does, just that I didn't want it to do that. Is it like FourSquare?

In a rhapsodic 4S/iOS5 review Gizmodo talks about Find My Friends being a game-changer. What does it do that's all that changey?

Part of me thinks it would be entirely cool to know where my friends were, and if they were accepting sociability, and then reality strikes that I'd always for get to turn Do Not Disturb either on or off.

I'm starting to use location based reminders for things like "Call client x when I get to the office". Combined with Siri it is pretty slick.

Thanks, le nubian and Consuela. I've been hearing good things about Pinboard but I'd had that last lingering question. Diigo fell through for me and I just ran out of patience waiting for Delicious to fix itself.

I'm starting to use location based reminders for things like "Call client x when I get to the office"

It determines that by GPS?

Back in the day I had the best phone companion software (pre-Android, it never worked with Android, and is discontinued now) that would do all sorts of Bluetooth proximity stuff with your phone and your Mac. Mute iTunes when the phone rang, caller ID display on the Mac, take actions on the Mac when the phone comes into range and vice versa. It was so cool.

But I haven't thought deeply about that stuff since then.

Although my rental car can sync with my phone. I just don't keep Bluetooth on for battery reasons. Not sure what the hit is.

Yes. It is doing that work based on GPS.

I would like my phone to be able to have different configurations based on location. That must exist, right?

So one profile when it knows I'm at work (either by GPS or by WiFi) which doesn't necessarily have the Doctor Who theme music, but full blast everywhere else, maybe something different on my home network. I also don't need my tablet to ring when I'm in the office. Just elsewhere.

Does anyone know if there is a place to sell your iPhone 4? (or if anyone knows someone who wants one?) I thought I saw something on the Apple web page about buying back iPhones but now I can't find it anywhere.

Stephanie, try Gazelle.

Stephanie, at&t or Verizon?

compare gazelle to apple trade in program. I did gazelle and apple's programs over the summer because for one of my computers, apple's deal was MUCH better.