Use a piece of scotch tape. Reuse the same piece to clean the screen in five passes or so ... just be careful not to smudge the screen with your finger when you're pressing the tape on. Pull up slowly and repeat as needed!
Slightly off topic - screen protection rather than just cleaning. On the outer screen I use "WriteRights". It is a clear adhesive screen cover that is meant for my Palm Pilot, to protect against scratches. I don't use them for my Palm anymore, but they are good for the VX4400 or my S105. You do lose some readability on the screen, but not enough to be a problem. You should be able to find some that are similar but cheaper than this brand. For my inside screen, I just use an eyeglass cleaning cloth every so often. Actually, talking about being neurotic, the other day I dropped my phone, which created some scratches from the pavement. For that, I used Macquires polish ( a polish that is meant to remove scratches from clear plastic). I used to use it with my old swatches to great effect.
