The FZ35 that Jerry and I posted links to will satisfy the requirement for light weight, and it allows you to control many of the parameters. The biggest downside of a "compact camera" vs DSLR is the inability to change lenses. But, the superzoom on the FZ35sure goes a long way to make up for it. I'm still in my 90 day return window, and wish I could get my hands on the FZ35 for 90 days.
The terminology can be confusing as well, Tom. SLR described the single lens camera versus the TLR (twin lens camera) -- such as the very popular Rollieflex or the MamiyaFlex (mentioned by Howard previously here) medium format film cameras. One lens was used for viewing whereas the other was used to expose the film. The twin lenses came in pairs as part of a single unit -- and were interchangeable (tele vs. wide angle and so forth). My first medium format camera was the MamiyaFlex.
The SLR allowed viewing through the shooting lens via the reflex mirror, prism system. Non-SLR's had separate viewing - tho not with a second lens of the same type as the shooting lens -- so the quality of viewing was much less. When the digital's came out, most were of that type as well - or with a LCD display of what the shooting lens was seeing. Nikon was probably one of the first to modify an SLR to become a dSLR, but others quickly followed.
Anyway -- my point here is that, to me, SLR and dSLR only describes the type of lens/viewing system that camera uses. My first digital was an Olympus 2500L. It was a "fixed lens" dSLR vs. a interchangeable lens dSLR. I doubt there are any fixed lens dSLR's anymore, but you see my point. My mother bought a Kodak box camera in 1923 that used 620 film. That "was" a point and shoot camera. You picked up, pointed it at the subject, and pushed the deal that activated the spring that opened the metal thingy that covered the lens.
What appears to have happened tho, terminology wise, is that a dSLR now seems to imply interchangeable lenses plus tons of other stuff that non-dSLR's do not have. And all other cameras are P/S's. And I find that "very" misleading. As Jerry points out, the gap between the features of a camera with a SLR viewing system vs. one that does not have such a TTL real time viewing, is getting smaller and smaller.
In addition to interchangeable lenses, and method of viewing -- the other biggy is the size of the sensor between the two. If a non-SLR and an SLR both have 10mp resolution - the dSLR's will be larger. So each pixel can store more "light" data and make the RAW a better digital negative to work with. Other items to look at are the speed of AF and other such items that Howard mentions. The side by sides are great for that. Flash sync speed and fastest shutter speed also come to mind. For example, I believe your XSi is 1/4000 sec vs. the FZ-35 is 1/2000. My 50D is 1/8000. BTW, each only represents one f-stop over the others.
Sorry if I've rambled -- but wanted to make the point of how misleading the current terminology can be. And it is too bad that it has categorized digital's into point and shoot vs. dSLR's . . . IMO!
