You can increase the ring-tone file size limit to 16MB from 300KB(BlackJack default). So, you can set your mp3 files as ring-tones. Moreover, you can restore the limit to 300KB if you want to.

PhotoAce is an innovative photo viewing application for Samsung Blackjack. It allows you to effortlessly manage and view photos on your BlackJack.
It has been downloaded 5,000 times for 3 months.

Here are a few applications that every Samsung BlackJack owner should try at least once for their phone. These applications are all free and all do an excellent job for their purposes.

Speed dial can be used not only to quickly dial numbers in your contact list, but also launch applications with [...]

This program allows you to quickly and easily reboot and shutdown your BlackJack by placing a shortcut in the start menu.

Schedy Mobile is an alarm and task manager for Windows Mobile smartphones. It can set an unlimited number of alarms and tasks with many ring types and scheduling to choose from.

This handy program allows you to change any and all registry settings on your BlackJack giving you the potential to customize your phone beyond normal means.