Whilst researching my latest project, I came across this beta guide from Microsoft.

Whilst targeted at SBS environments, it could be used in any environment with Windows and Exchange Server 2003.

The Small IT Solution for Mobility uses Windows Mobile-based Pocket PC (Phone Edition) and Windows Mobile-based Smartphone devices. The solution helps Microsoft® partners plan and deploy a mobility solution for small business customers. The solution infrastructure is built using the Microsoft Exchange Server 2003 components of Microsoft Windows® Small Business Server 2003.