Link2 - Practical BlackBerry Utilities
TagIt! - keep e-mails on your BlackBerry organized
TagIt! is an innovative application which brings the concept of tagging on BlackBerry.
With TagIt! you can create as many tags as you wish and assign these tags to e-mails.
These tags can be later used to search for all relevant e-mails. Requires OS 4.0 or higher.
Get the demo (.zip archive) here.
OTA download here.