Here's a Mango App that will let you pin your favorite photos on the Windows Phone Start Screen. As with other Mango Live Tile apps, such as Sticky Tiles and NFL Live Tile, the interface is short and simple.
You have one page to select the image from (one for either side of the tile) and one page to enter optional text. From there you pin the app to your Start Screen and the tile is generated. There's also a tile count area where you can enter a reminder such as a date or number of days until an event.
The only downside to the app is that your only limited to one tile. Still, it's a nice way to pin a photo of your pets, kids, girlfriend or wife (but not both) on your Start Screen. If you're running Mango, Live Tile Now is a free, ad-supported app and you can download it here (opens Zune) at the Marketplace.