Facebook is all about sharing, and The Gap has an ingenious promotion on the Baby Gap tab of their Fan Page. The simple splash image has a link to one of their photo albums where fans can upload pictures of their babies wearing their favorite Gap denim gear.

The Home Depot has built a bit on the shareability of Facebook actions with their DIY Gifts app. From Home Depot’s Fan Page, you can grant the app access to share your gift purchases with the recipient and your friends. While this approach may not work for everyone, it’s a step toward increasing consumer visibility on Facebook — a growing trend.

Some companies go all out when it comes to their Facebook presence, integrating fully fledged mini-websites right into their Fan Pages. Adidas sneakers is a good example. They’ve added a multimedia content hub under the tab “Your Area” that offers photos, videos, and events based on your region. The site is built entirely in Flash and isn’t all that interactive, but it offers a rich media experience without ever leaving the boundaries of Facebook.

Dell’s Design Studio page is another example of a full-tilt Flash site inside Facebook. This one lets you browse and tweak custom artwork for your new laptop before linking you over to the corporate site to complete the purchase. You can also share your design choices with friends, all without connecting a single Facebook app to your account.

Walgreens does it very simply. Their landing page is a nice branded splash image that simply touts their “Exclusive Offers for Our Facebook Fans.” Their promotions are in their updates, but this simple, static custom page encourages users to become fans without any bells or whistles. They leave the deals to the built-in functionality of Facebook, and your business can too.