Here's an intersting use for the camera in the 8100. Smartpox: Bar Codes For The Web smartpox » welcome
Smartpox.com is an interesting crossover between the online and offline worlds. The technology allows users to encode URL links, phone numbers, email, and text into 2D barcodes. These codes can then be read using a cameraphone running the J2ME Smartpox reader. So a Smartpox is essentially a 2-dimensional barcode, which contains data that can be decoded using the Smartpox reader in a mobile phone.
(edit: as soon as they start supporting the blackberry 8100)