The following are examples of Mob Progs that I've created (or that others have). I'm not going to go through and explain them.. You can get help on mobprogs here and variables here
Prog 1
A pixie that goes through, and detects your sex, asks if you'll be her friend if you're male, kills you if you're female.. If you say yes, she rewards you, if you say no, she kicks your ass.. It's a two part prog.

The Greet Prog
if sex $n < 2
wink $n
say would you like to be my friend today?
say I could really use a friend
else
kill $n
endif

The Speech Prog ($n says yes)
if sex $n < 2
say awww, how sweet. Thank you so much. Here, take this and treasure it forever.
mob oload 32420 1 room
mob force $n get ring
else
kill $n

The Speech Prog ($n says no)
say well damn. I guess I'll just have to kill you then!
say you know, you woulda been better off as my friend.
kill $n

Prog 2
This is just a simple prog that lets a mob (Rattan) check a person's level, and if they're a level higher than 200, he issues 'em a bold challenge
if level $n > 200
say hey $n, think you can take me?? You can have my weapon if you do..
say personally, I don't think you got the balls to do it though, $n.
laugh $n

Prog 3
This is quite a well designed prog. I wish I could say I'd done it, but I can't, it's part of a quest area generated for DR. It detects if you're carrying an item, then re-welcomes you, if you are, or gives you one if you're not.
if carries $n 30900
or carries $n 30902
say Nice to see you once more, $n.
else
mob oload 30900
give wassail $n
mob oload 30902
give gingerbread $n
say Happy holidays, $n.
endif

The last two were strictly greet progs, an example of how one might use a few of them.. Enough examples for now. I'm sure I'll add more later.