Over Thanksgiving, I broke out the S&W book, some dice, and "Dyson's Delve" (an old-school friendly dungeon system) for some impromptu gaming.
I had wife&kids roll up new characters on the spot, going hard core with "3d6 in order, swap two". Stats ranged from 7 to 14, with most in the 9-12 range, so no superheroes. My players chose very standard roles for themselves - Human Fighter, Elf Thief, Human Magic User. The setup was classic "Junior High" level D&D - the players are in a Tavern, when a guy named Dyson comes in, announces that after losing his party (again), he's had it with adventuring, and will give his treasure map to anyone willing to buy him a solid meal. The players fed him, got a few details about the dungeon from him, and set out the next morning.
I'll spare you the details this time, but everyone had fun and want to play more with these characters. My youngest player even told me she really enjoyed the game "even though we just rolled up characters and wrote them down on blank sheets of paper."
I think my success in this game was due to a number of factors.
First, we kept it VERY simple. We only had blank computer paper, dice and pencils. I sketched the parts of the map as they went along, describing the room and not worrying too much about scale. S&W's combat sequence is very simple, with per-side initiative and straight forward attack options. I didn't worry about movement rates and such, since the area was small enough.
Second, I tried to be more descriptive in my narrations. So instead of telling them that the passageway ends in a roughly 20x10 cave with a smooth floor, I'd outline out a rough region on the paper and say, "the passageway opens up before you to reveal a larger room. Some stalactites hang from the ceiling, but the floor is mostly smooth." I also tried to be less "there's a cave here with 10 giant rats" and more "down the passageway, you hear the squeaking of many creatures. As you approach, you can see that you've found a nest of giant rats, and their eyes glint hungrily as they turn from their scraps of food to face you."
(I'm not saying I didn't go for atmosphere before, but this time I completely disregarded any mechanical descriptions, like room sizes, etc. and relied on the sketched map to convey the rough size and shape of the room, and narration to describe the overall feeling and relevant details.)
And finally, I tried to keep some whimsey in the game to balance out the creepiness. For example, when the Fighter made his save against a ghoul's attack, I described the icy feeling of paralysis coming over the character, and his force of will to shake it off - "Not Today!" the player exclaimed. Later, when the M-U cast Sleep on a bunch of rats, he only got all but one of them. The little guy hunched over, shuddered in effort and with a baleful squeak, said something in rattish that probably means, "Not Today!" before he charged in to attack.
So, after the adventure, the players found themselves in possession of around 1000gp each. (In S&W as in all old-school D&Ds, gold is XP, so players tend to have a lot of it.) The M-U started asking about costs for making scrolls and stuff. Normally, Magic Users don't make scrolls at low level, but that ability is one of the things I really like about Pathfinder, so I came up with this:
An M-U can make a scroll of any spell he knows for 100gp + 100gp per spell level. So a 1st level scroll costs 200gp, 2nd 300gp, etc. This matches up (sort of) with S&W's treasure generation rules, and means that (as long as they keep finding gold), M-U players can bring the hurt. But a smart player won't blow a 400gp scroll to get less than 400gp of profit, unless death is on the line.
Also, I figured that an M-U can spend gp on researching spells. For any spell in the rule book that the M-U doesn't know, he can spend 100gp (double each level) to re-roll his "chance to learn" percentage. Twice that if he does not have access to either a spellbook or scroll containing that spell to work from. At high levels, this research is staggeringly expensive, and it's probably more cost effective to find high-level mages and steal their spell books. Even at moderate levels, it's worth throwing a few 1000gp at some adventurers to steal a book for you, if you know it contains spells you want. This works as motivation both for players and patrons.