Here’s a collection of useful tools for the windows mobile developer:
NETCF 3.5 Power Toys
Power Toys for working with .NET Compact Framework 3.5. The Power Toys for .NET Compact Framework 3.5 provides several tools for evaluating performance, obtaining diagnostic information, configuring and working with the .NET Compact Framework. Download here.
ReSharper Visual Studio Add-in
Not a tool spesific for device development but definitely a must-have tool for Visual Studio development. The list of features and goodies is too long to even start here. It’s freeware for classroom or training use, $49 for an academic license, $199 for personal license and $349 for commercial use. As a commercial developer you’ll made the purchase worth after a day or two. Download the 30 day trial and you’ve saved enough to buy a 5-pack :)
SOTI Pocket controller pro
View and control your mobile device using your desktop computer screen, keyboard and mouse with Pocket Controller. Pocket Controller is imo way superior to the RDC from microsoft. This is a must-have for on screen live demos. Requires you to install a Pocket Controler serverapp on the pda, and it cost’s $35.95 per license. The Pocket Controller remote registry editor runs circles around the Visual Studio Remote Registry tool. Buy or download trial from here. Breathingtech.com has some more info on Pocket Controller.
Microsoft Remote Display Control for Pocket PC
Simple no nonsense remote display control for pocket pc originally written for Pocket PC 2002. Usable freeware alternative if you don’t want to use the SOTI Pocket controller. As with SOTI, the Remote Display Control application display actions on a Pocket PC, including user input, remotely on the display of a desktop or laptop personal computer. Remote Display Control uses TCP/IP, and it can work with ActiveSync connections via Ethernet or dial-up. Download from here.
My Mobiler
Another remote display controller. freeware has more functions and is a better alternative than Microsoft Remote Display Controller. Download from here.
Got a favorite tool, Post link and description as a comment and i’ll add it to the list.

Thanks for this, I did a few searches and only found commercial products and the majority of them were absolute crap.
I also didn’t know that Microsoft had a solution for this either, but what do you know?