Timewatch's timesheet entry system for PDA devices supports literally any PDA device including Palm OS, Pocket PC, Ipaq etc.
TIMESHEET ENTRY VIA PDA

Mobile users can enter their timesheets wherever they are.

Optimized for the screens of PDA devices, the pdatime™ entry option provides a fast, easy to use timesheet entry that invites the user to enter and post timesheets as the work is done, allowing for immediate posting for analysis and reporting.
Standard Features include
>  Timesheet entry
> Optional Expenses entry
> Only lists the user's jobs / projects
> With Scheduling, prefills assignments of Today's Jobs making entry even easier.
> Stopwatch Facility
> Notes entry
> Review previous entries
> Submit to Manager for approval
> Auto missing timesheet alerts available
> Utilizes wireless LAN or Bluetooth Cell connection to allow timesheet entry anytime / anywhere
> Supports Ipaq's and most other systems running Windows CE, Pocket PC 2000, 2002 & 2003