My mom and I allow the OSPD in our friendly games. They are small enough you don't need a crane to lift them and, most importantly, it's house rules. If it ain't in there, you cain't use it. We have several editions and use all of them if necessary. Mom used to play with a neighbor that combed massive dictionaries and had a handwritten notebook of all the two and three letter combinations she called "words", saying "Well, they're in the dictionary."
I trained my friend Ruby to play the friendly way as well. What I can't stand is someone agonizing for 15-20 minutes
on every single play 
and then tightening up the board so you are lucky if you can find a spot for two or three letters. When Ruby gets in this mode, we have to play a couple of Speed Scrabbles without scoring, just to loosen things up, like my frustration levels
Edit 1 I forgot the P.
Edit 2 Ach! I forgot one of my favorite things...theme Scrabble. It's fun for the first word to set the theme. Naturally, there will be some plays that can't follow the theme, but it's the effort that counts.
