What's the difference between an SLR and non-SLR? An SLR camera will allow you to 1) photograph fast-moving subjects; 2) make photos of relatively higher image quality in low light conditions without having to lengthen your exposure time. 3) take photos that enhance the texture of your subject.
For quick photos on-the-go and short movies still I depend on my rugged little Casio.
But I'm having a lot of fun -- and I would like to think some success -- lately with my Nikon D40. It's full-featured digital SLR. Olympus has a model that's a tad smaller, but the Nikon D40 and D40X are also small and light. Most importantly, they are easy to grip. You don't need a second hand to change the settings. The D40 is true masterpiece of ergonomic engineering. And it feels solid and fairly rugged. It looks and feels like a camera costing ten times as much -- and more importantly, so do the results.