I can't find a list of all apps I've ever purchased ( paid $ free). From my iPhone
If you are running at least 4.3, you can use the iCloud beta to see every app you ever purchased. If you open the Updates tab of the app store, there should be a Purchased button at the top. Tapping on this will give you a list of every app you purchased on your current account. I would suggest choosing the "Not on this iPhone" tab so you don't have to look through as long of a list. Once you find the app, tap the cloud icon to download it.