My Favorite PDA Apps

Today I thought I'd share some resources that I rely on again. This time, for the mobile world. For reference, I use an HP ipaq rx5915 Travel Companion runninng Windows Mobile 5. Some of these come in multiple versions including Palm, too.
BeyondPod - I use this program for my podcasts. It is free and very easy to use. The layout is simple and easy to understand. Entering new feeds manually can be tedious if you don't have a good keyboard, but importing an .opml file is a breeze.
BeCrossword - This crossword puzzle program costs $14, but it has been worth it to me. You can download new puzzles every day from many sources, most of them free. New York Times charges a subscription fee for their puzzles, but there are many free sites. You can import any puzzle that is a .puz file. This keeps me sane in long lines, waiting rooms, etc.
DoInventory - This is the inventory program I use for my Shop. It costs $30, but Wakefieldsoft does run specials occasionally. It is very customizable, and can be synced back and forth from PC to handheld. It even has support for barcode scanning.
GPS Tuner - This is a great off-road GPS program. I use it for Geocaching, and it would also be great for hiking. Not to show my faults, but I also use it to find our car in large parking lots... At $30, I have more than gotten my money's worth out of it, and still use it heavily.
Can't Stop Solitaire - This solitaire program may cost $30 (watch for specials, though), but you will be playing it non-stop. Seriously. They weren't kidding when they named it "Can't Stop". There are 200 different games. Several are variations of each other, but there's certainly enough variety to keep things fun. Like the crossword puzzles, it's very good for unexpected downtime.
Grocery Day - I've tried a lot of shopping list programs, but this one is my favorite. And free, to boot! Very simple, no-frills interface, and you can keep multiple lists. I use it for groceries, store supplies, and I even have a list of questions to ask my doctor that I never remember when I'm actually in the office.
Today Agenda - This free Today screen plugin has been invaluable to me, what with my ADD. It is a more adanced Task management program. I use it as a perpetual to-do list for things I need to check off every day.
MyCustomers - This $10 program is a useful customer database application. I have not yet used the import/export features, but I do like it so far. There may have to be a follow-up review after I've used it more thoroughly.
What are your favorite mobile applications for fun, business, or whatever?