[Introduction] [Screenshots] The Smartphone GPRS Traffic Monitor by Efficasoft, allows you to monitor GPRS data usage both graphically and numerically on your smartphone, thereby giving you more control on your mobile phone bill.
Written in native C code, the Smartphone GPRS Traffic Monitor is less than 50KB in size and is especially designed to consume minimum system resources.
Does not work on your phone? Try the Special Version 3.51w!
Fully supports Windows Mobile Smartphones (2003, 2003SE, WM5, WM6), Square, QVGA (240x320) and landscape screen.
Features 
Monitor multiple connections simultaneously.
Home Screen GPRS traffic display with easy switch between Day/Month views.
Friendly interface design, detailed usage statistics at a glance.
Connection status and IP address display.
Multilanguage support - English, French, German, Italian and Portuguese.
Cost: $7.95
http://www.efficasoft.com/gprsmonitor/index_sp.html
Acknowledgement
Thanks to Manuel Boenke for the German translation, and his great help in beta-testing Smartphone GPRS Traffic Monitor for Pocket PC v1.1!
Thanks to Jean-Roger CONDAT of
www.MobiSmart.net for the French translation!
Thanks to Lee Sainsbury and James Whittaker for testing v3.02 on Orange C550!
Thanks to Dimitri Spazov of
www.portalPPC.com for the Portuguese translation!
Thanks to Inter-Ware srl -
www.inter-ware.it for the Italian translation!