I wanted a compact waterproof camera, and I hate proprietary requirements, so the Olympus was out due to the xD, leaving the W60. While the xD is not exclusively proprietary, I've heard that in order to unlock some feature(s) you have to have Olympus brand xD, which was the case when I bought my first digital camera (a 1.2MP Olympus w/ SmartMedia).
I want to be able to safely stow the camera in the smallest feasible footprint, so sans case is desired. I got a screen protector for the W60's display screen, but the lens's screen was still unprotected and I didn't want to see what would happen to images after putting a screen protector on that lens. That left me wanting a lens cap, which I didn't manage to find after some quick looking.
The lens area thankfully sticks out a smidge. I measured it to be 38mm in diameter, so I looked for plastic caps with that internal dimension and found and used the following:

This had the shortest depth I could order, so a little cutting was desired. The inside depth was deeper than the outside depth, so I compensated and gave myself a 0.5-1mm margin. My pipe cutter was too small, so I used a PVC cutter and a pill container to plug the cap for easier cutting (so the sidewalls wouldn't bend). Once cut, I drilled two slits for a rubber band, and connected the said rubber band. Since I'm now I'm a happier camper, and 'cuz Cat will likely take credit for me being a W60 owner, I thought I'd share.
My finished product:



Fig. #don't care - rubber band placement with the lens exposed.