Camera shopping: shutter lag?

Any of the DSLRs will have very minimal lag (depending on the lens and shooting conditions). Many point and shoots don't have much any more, especially if you prefocus if available. I would recommend you go to a store that has a good selection of point/shoots and/or DSLRs if you are interested and just try them out. See which feels best to you, has the features you want, and minimal lag. Be sure to try to take some pictures in different lighting if possible. You can sometimes get a lower light shot by focusing down on the floor in a shadowed area.

I prefer my DSLR, but also have a point and shoot for those times I just want to have a camera with me, but am not necessarily planning on taking a bunch of pictures.