Few things go together like photos and weddings.  Few things can bring an internet connection to a standstill or fill up an e-mailbox than big photos.  Not a happy combination.  Microsoft has a plug-in for Windows XP called the Image Resizer Powertoy.  The Image Resizer helps you quickly resize a photo to a smaller file size so you can e-mail it to your friends without killing their mailbox.  It's a small download which installs easily, and adds an option to your right-click menu.  Find the photo you want to resize, right-click, and choose the size you want the file to be.  Windows will copy the file to the size you selected, ready for you to send.

If you are your fiancee' are photo buffs, and you own a Nikon or Canon camera, you can look at the Windows Raw Image Thumbnailer.  Microsoft's description says it best:

RAW image capture is preferred by many serious-minded photographers to preserve all the subtle color and detail possible from digital cameras. However, until now it has been impossible to view thumbnails and previews for RAW images in Windows without use of special software.

The Microsoft RAW Image Thumbnailer and Viewer enhances the Windows XP photos experience by providing thumbnails, previews, printing, and metadata display for RAW images from most Canon and Nikon digital cameras. This tool enables advanced digital photographers to organize and work with RAW files directly in Windows Explorer in much the same way as with JPEG images. No more "guessing" which image is which!

This is a large download, so make sure you have time or a lot of bandwidth.  Also, check out the Readme file first to make sure your camera model is supported.