<map lat='47.4346809406041' lng='9.38913971185684' zoom='14' view='0' float='right' /> St. Gallen is a city in Switzerland.
To hitch out in this direction, there's a spot at the Sankt Fiden exit. There is a bridge over the motorway from which an on-ramp comes down to join the motorway. You can just stand on the upper end of that on-ramp -- it doesn't look like a very good spot, but Zenit has never waited longer than 10 minutes here. Take bus 1, 4, or 7 in the direction Stephanshorn, Guggeinen, resp. Neudorf. Get out at the St. Fiden stop and walk to the bridge.
East towards St. Margrethen, Bregenz, Austria, Germany N1
To hitch east, use St.Fiden point described above but in the opposite direction. It is near the hospital, just ask people for the way there and walk towards the on-ramp. Just before the motorway officially begins (and where it becomes illegal to stand, see the big green sign) there's a turn-off with almost no traffic, so by standing there you'll be easily seen by cars. Note that there's is little traffic and most cars will be local, most likely going to the border town of St. Margrethen.
Once you found a lift to St. Margrethen ask your driver to drop you off at the border crossing between Switzerland and Austria. Hitching on from there is easy.
Sleeping, Eating, Internet
In the southern part of the city, there's a little hill called 'Freudenberg'. It's well-known among locals for the 'Drei Weiheren', three artificial ponds for free swimming. The hill and the ponds are within walking distance from the motorway (ask locals for directions if necessary) and this particular place might actually be worth getting dropped off in St. Gallen if you happen to pass through in the afternoon, not knowing where to spend the night. Not as much for the ponds -- there are better lakes in Switzerland -- but for the view over the town and Lake Constance (German: Bodensee) in direction north-eastward, from atop the Freudenberg as well as on Mount Saentis (southward, the large mountain with the antenna) and the possibility to sleep right up there in the meadows, undisturbed and peacefully (stargazing and morning swim in the ponds included). You can also have a campfire and there are public BBQs.
For free food, check out the McD's at the Marktplatz Bohl, the central square. Excellent table diving, find the code for the toilets on the receipts. For computers to use the internet for free, check out the Stiftsbibliothek, the Abbey Library. Don't enter the exhibition, but ask for the computer.