Summoning: we use summooning as "magic - Poof" to bring in Monsters or Animals. I have allowed the PCs to choose whether to "random pull" from wherever these things come from, or to "specific Pull" a recurring entity, thus kinda forming a relationship with them. Ine either case, the magic clearly states that the summoned creature perfectly opeys, and vanished when dispelled, killed, or expires the time limit. This is tied also to the Magic that snatched it and at a minimum restores life to the summoned creature of it was killed. Of course, if you keep getting the same goblin and he keeps getting shwakked, your mileage may vary if he's not MIB Flashed to reset, and actually REMEMBERS always dying with you. "Oh, gods, not YOU again". I have also developed a high level spell (used BY creatures like Dragons and Demons, various Dieties, ArchMages and High Clerists and such) called "Monster Summoning YOU" that does indeed snatch PCs from the multiverse to do a Geas-like bidding for some powerful beings. If they live, they get XP and a nifty story. If they don't, they get "returned to sender" no worse for wear, and yes, I let them remember. (The magic also restores expended/lost/broken magic items) It makes for an interresting plot hook tool as the characters become aware of other things of great import going on, and may voluntarily seek them out to join, or to try to atone for.
On the Road: I have run the whole bank of extremes. I have stayed in the Radisson in Milwaukee (both in the Suite and in the Car-Park), as well as the other walking-distance lodgings from Marquette Universitry Dorms to the localized Indianapolis convention center hotels. (Rocking the Gen Con, Baby!) If you have a room, treat it nice. If you have to share (done 4+singles, 2+2, and 2+1) be courteous of the roomates. We've done just us in the Van, and we've done 4 of us in the Car. This takes coordinating access to other friends or even outtreaching as far as the Truck Stops to access showers.
For Smaller cons or just gaming with friends enroute along road trips, staying with others as a guest works well if prepared and coordinated. If you are local to the con and willing, be a host to travelling gamers you know. On either side of that equation, DBAD.
Harpies are all kinds of fun, can easily be used as information sources, and why the hell not have them "own" and "USE" the magic items/weapons in their listed treasure? WTH, is this the Goblins Warcamp in THuntworld? "ooooooh, never never use the nifty magical bow or wand in the poorly locked chest". Meh. You want my wand of Fireballs take it from my cold dead claws (especially if you want to take it with "most" of its charges left.)
Give them spellcasting, give them thief skills, alter their alignment for a fluke, put them in alliance with or conflict with other things wanting to raid the suitable ambush sites along the trade roads. Remember that the Harpies have no use for the Females in a party other than as food, so they are likely to focus their attacks on them, to leave the males for....other uses first.
X2: Castle Amber, is very railroady, but in a good, one-shot kinda way. Still a slightly skewed POV as it is a gaming foray into a fictional novel universe. I've always kinda felt that it was more a fanservice for a niche author. In general I've found Amber (Like Dragonlance) suffers from "good to read, bad to play". But...it has been fun the several times I've run it, but the most fun I've had with it is the time I opened up the floodgates and called for "any level character out of any game system" and ran it like a Dr. Who episode on bad acid. 18 Players running 26 characters compiled from D&D, Toon, Traveller, Star Trek (Fasa), Paranoia, Gamma World, 007, and Recon. Then I freeformed running the game by full DM fiat for conversion of abilities and equipment effects across the board to accommodate everything.
_________________FULONGAMER aka Johannes M. Bowers
It's not My planet Monkey-boy! / I Waste Him With My Bowcaster!
THIS is my LIGHT-Stick!, The next one of you Furry Tree-Hugger Yub-Yub Primitives EVEN TOUCHES me...//FZOOOK!//