A review of the Pentax Optio S4i digital camera is available at imaging resource.

This is part of the review conclusion:
“Overall, the Optio S4i is amazingly full-featured for a subcompact model, delivering good color and tone in an incredibly tiny package. If you’re mainly looking for an ultra-compact camera to snap photos under daylight conditions, the Optio S4i is hard to beat. On the other hand, if you anticipate much indoor and after-dark photography […], you may want to consider another model.”