[Frankenstrat2]

Originally Posted by Johnny Guitar

A guitar which is played when laid on your lap is a "lap steel"; it may be a Dobro or any other guitar, it may have a square neck or round neck, acoustic or electric, it may have six, eight (maybe even ten?) strings -- it is a lap steel guitar.

Caveat to the above: Junior Brown is an amazing lap steel player but plays an odd double neck guitar which is esentially a Telecaster and a Fender type lap steel. He plays it standing up (not on his lap).

A pedal steel guitar will be on a stand (four legs typically). It has pedals and knee levers which change the tuning of particular strings in different ways. A pedal steel is supposed to be very dificult to learn to play.

I think I raised this question here months ago.
I came to the conclusion that lap steel mainly refers to solid body electric 'planks' with pickups. The original 'Hawaiian steel guitars. They can be 6, 8, or 10 string even double necks, but no pedals. Pedal steels are a much more recent invention.
A dobro is NOT a lap steel.
Dobro is often a resonator guitar, and is played lap style. They are almost always 6 string. They can be square or round neck. The square neck is a giveaway that it was never intended to be played upright.
Dobro and lap steel share the fact that they are not really fretted instruments. They are played only with a steel bar. The nut at the bridge is much higher than a guitar set up for bottleneck.
Bottleneck guitars, slide resonators and electric bottleneck slide guitars usually are played upright and usually have frets. I have seen fretless electric guitars set up for bottleneck slide. The action can be high, but not so high that you cannot fret the strings to the fingerboard.

If anyone disagrees, I'm open to being corrected.