A utility called PhotoResizer 1.0 will let you copy and resize JPG images right on your Windows Mobile device. This can be quite useful if you have a camera on your device. With PhotoResizer you can reduce pictures to a size that works on your PDA (320×240 or 640×480 for example) and use up less storage than the originals. This can also be handy when you want to email someone your pictures.
PhotoResizer will let you select source and target folders graphically, select target size and quality, and gives you the option of seeing a thumbnail during the conversion.
PhotoResizer 1.0 is available for free from www.FreewarePocketPC.net. It requires that you have the .NET Compact Framework 2.0 installed on your device.
Source: PocketPC Paradise