I have a small boat and have been NEAR several places that looked real fishy but would be too difficult to get a boat into with out scaring everything off. I have sat looking and wishing I had a little paddle boat that I could toss into my bigger boat and go from there. Just a thought now.. Anyone doing this? How practical? What is a good, small, light, kayak? What's the best type of kayak for this kind of activity?

Have you considered getting a float tube? Might be a better solution if you want to bring it on your boat with you and easily jump in the water and kick your way over the the fishy looking areas. It would definitely be easier to haul around than a kayak. Just a thought...

I have seen some guides leaving out of Goose Island with clients and a couple of small kayaks strapped down on either side of the center console. I have seen a few places, myself, that I wish I could sneak into. Tried wading....2 feet of water and 2 feet of mud....not wader friendly. Could power the boat up into and scare off all of the fish.
I agree, the tube if deep enough or you are on the right track with a kayak. There are so many companies out there and so many different styles and price ranges. Try some out and go with what you are most comfortable with.

Here is a little one that is light and might do the trick.

http://mainstreamkayaks.com/boats/sportsmanseries/pages/streak-s.html

Sounds like a good idea, if only for the exercise
You'd obviously need a small boat, and probably want to be able to stand in it so you can better locate the fish. And if you stand for casting I suppose you'd like to paddle standing too
If I'm correct have a look at the 10' W1:
W1
I wonder if it's possible to drag this boat behind a motorboat for some waterskiing