TopGuest

Without a doubt, Instagram is the breakout app of 2011. If you don't already have the artsy iPhone photography app, you're totally missing out on the fun, as well as these great mashups that use Instagram's API to produce some cool third-party apps and sites.

See why Instagram is worth a download, then browse these other ways you can incorporate the photo-sharing goodness into your life below.

• Postagram — Send an Instagram postcard right from your phone with this app that lets you send one of your already-saved Instagram pics, or snap a new one. Then, write a message, insert shipping address, and your recipient will get a glossy postcard with removable (pop-out) image. So cool and so cheap — each Postgram costs just $1.
• Extragram — A sleek web client for your Instagram feed, you can check out the day's popular photos, your feed, and search for people and tags without ever breaking out your phone.

See the rest after the break.

Checking in on Foursquare or other geo-location apps can get you more than mayorship — it can get you some pretty sweet deals if you know where to look. More and more businesses are offering up discounts for their mayors, frequent customers, and even passers-by, kicking back a little coin just for visiting. Find out how you can save money, get a great deal, and even make a little cash, just by using Foursquare, Loopt, or these other location-based apps.

• Foursquare — The current king of geo-location apps, participating Foursquare businesses can offer deals and discounts for mayors and frequent visitors, ranging from free frapps at Starbucks to 25 percent off at stores like Sports Authority.
• Loopt — Loopt has been known to offer an automatic 25 percent off purchases at Gap and deep discounts on Virgin America flights, and even show you available rewards near your current location. Now it's even integrating Groupon's Groupon Now deals into the app, so you can find great deals on the go.

See the rest of the list (there's quite a few) after the break.

Topguest, a membership rewards program that pays its users for checking into locations using services like Foursquare and Loopt, has a new partner: photo-sharing service Instagram. Yesterday, Topguest began rewarding users posting photos of certain locations on Instagram. To take advantage of this new functionality, just link your Topguest and Instagram accounts.

In celebration, Topguest-friendly airline Virgin America is sponsoring a competition: the users posting the most-liked Instagram photos taken at Virgin America-related locations (like airports and airplanes) will win 1,000 Elevate points — Virgin America's loyalty program.

The partnership allows Instagram users to connect the world around them (beyond just taking photos) and gives Topguest users an opportunity to earn more points just by taking photos of things they would naturally take photographs of anyway.

Remember when I told you about the hospitality-focused location service TopGuest? At the time, it was just picking up steam, but now the service, which is used in conjunction with Facebook Places and Foursquare, has teamed up with Virgin America to introduce a perfectly-timed holiday promotion.

Earn 25 extra Elevate frequent flier points just by checking in on TopGuest at any Virgin America airport terminal or baggage claim. You can rack up 50 extra points per trip, which can then be used toward future flights. Easy enough, right?