I can get these (MagnaBrite Delta 77/77G) for $20. Can they be used with the std fresnel and if so what result could I expect, eg: bigger/smaller projected imade, smaller box, etc. from what I could find it's a 77mm diameter, not sure about the focal length. If it can't be used on its own can it be used in conjunction with the std kit in any way?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...890227&tc=photo

Nope, used for a small CRT screen 3" or less i believe.

Does the size of the LCD matter? Surely it's a matter of placing the lens within the focul distance of the fresnel so that the enitre image "fits" in the lens or is it not that simple?

Yes you are right but these projector TVs usually have the lens mounted winthin 1/4-1/2 inch of the CRT so the focal length we are talking about is 1 inch or less. I'm not sure about your lens but in general these lenses have very very very short forcal lengths so can "see" a 15" or maybe even a 7' panel.

it is called the FOV (Field of View) of the lens, meaning what can it actually see when focused on the opject to be projected, and the FOV of such a type of lens is very small as mentioned above in previous post.