GeoRing ($0.99) lets you either specify any song in your library as your ringtone, or allows you to use playlists to set random ringtones for each incoming call. But, as you might have guessed from the name, that’s not all it provides, either. The app will also geotag and log your incoming calls, telling you how long it lasted (to the nearest second) and letting you see where you received it on a built-in Google Map.

GeoRing takes advantage of Apple’s multitasking capabilities (introduced in iOS 4) to function. For it to work, you have to open the app once and select the songs from your library that you’d like to use as ringtones. As long as you don’t reboot your phone or kill the GeoRing app in the multitasking tray on your iPhone, it’ll play one of your selected songs at random whenever you receive an incoming call. The app will play the track over whichever ringtone you’ve selected as your default, but the app’s developer has figured out  a way around that limitation. You simply need to download a free silent ringtone from GeoRing’s support site (or create your own), sync it to your iPhone, and set it as your default ringer.

It may not be a perfect solution (you can’t set specific songs as custom ringtones for specific people, and if you forget to relaunch the app after a restart you could miss calls), but it’s the best way to enable access to your entire library as potential ringtones without jailbreaking or time-consuming conversion. It also raises the question of why Apple doesn’t put this right in iOS Settings, if it’s okay with a developer building a complicated workaround. Are iTunes ringtone revenues really that lucrative? Considering that the process for buying them requires almost as much input as creating them yourself in Garage Band, I somehow doubt it.

Related content from GigaOM Pro (sub req’d):

• Can Social Media Save the Music Business?
• Mobile App Developer Survey: Profiles, Platforms and Monetization
• App Developers: Are You Ready for HTML5 and Metered Data?

Making ringtones with YouTones is, as the name implies, mostly about you. You singing, you swearing like a drunken sailor, you doing pretty much anything you can record with the iPhone’s mic. Yes, we realize how dangerous this could be. But it could also be a lot of fun, plus it’s cheaper than buying ringtones from iTunes at a buck a pop, and you don’t need to be near your Mac if you’re struck with the impossible-to-resist urge for a change in your call notification habits.

The app sports a nice background/splash screen, and the home page that pops up tells you exactly what to do to get started: pick a theme, record, download or share. Themes are effect sets that transform your voice. Examples include “Crazy Toad,” “Cousin Billy Bob,” and “Drill Sargeant,” and each sounds pretty much like what the name would imply. There’s even “Dark Lord,” and you’ll never guess who it sounds like. Hint: it rhymes with “Darth Nader.”

Overall, kind of silly and pointless, which describes most of the app store. Handy if you really want to annoy the heck out of your friends by setting your ringtone to “Breaking news, I’ve just received word that…yes, it looks like I am indeed receiving a phone call.” using the News Story theme. Which will never get old. Ever.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• Mobile Q4: All Eyes Were on Android, 4G and the Rising Tablet Tide
• Report: A Mobile Video Market Overview
• In Q3, the Tablet and 4G Were the Big Stories