Hi Jim,
To install an spp file, you just need to copy the file into your "My Puzzles" folder.
Unfortunately, Pocket IE makes it very difficult to download an spp file directly from the device, since it wants to display the contents in the browser instead. A new feature planned for an upcoming release (a free upgrade) will make getting spp files much easier.
In the meantime, you can do the following:
First, use File Explorer to create a folder named "My Puzzles" under the "My Documents" folder on your device. (This folder will already exist if you've installed one of the puzzle pack cabs from the puzzle download page.)
Then, download the spp file to a PC and copy it to your "My Puzzles" folder using ActiveSync.
If you really want to download spp files directly from your Treo and can't wait for the update, you can try reading a really long document about downloading files on a Windows Mobile device: "
The definitive guide to downloading files, images and saving Web pages with Pocket PC-based Web Browsers".
I didn't find it very useful (except to underscore how difficult it is to download files on a Pocket PC), which is why I'm adding a special feature to the game make this easier.
-David