With a cast iron tub you can purchase shower curtain liners with magnetics in the bottom. I have used them, can't say I notice much difference.

Is this for a shower or a tub? I've seen shower/bath curtain liners with magnets already in them toward the bottom so they will stick to a tub if the tub is magnetic. This may help you with a shower as well, if there is some way to place something magnetic behind a tile or in the grout, but I will leave that for the tile experts here. If you are using it for a tub (or even a shower), most liners I've seen have a row of little plastic suction cups on each side that you just press against the tile to make them stick and keep the water from getting out. The packaging on the curtain liner should tell you what it has. They are clear plastic and not easily seen, so you can still have an elegant look.

Thanks for your replies. This is for a tub.

Am not worried about the bottom, I will use a hotel curtain that has a twin-skirts so one flap goes inside the tub, when taking a shower. No worries there.

My problem is with the sides. Suction cups, I don't believe they work that well unless I make sure both surfaces are reasonably dry and clean. Am looking for a no-thinking, no-fussing solution, hence the magnetic strip idea.

I have a shower liner with the tiny suction cups and they work great, whether the surface is wet or dry. It' a pretty fabric liner with a tone-on-tone stripe, machine washable. I didn't have to glue any magnets, install anything behind the tile or search for a liner with a special metal strip. No fuss, no muss. :)

I have one of those polyester liner/curtains and it has suction cups. They are useless because they don't stick. So water does seep out onto the floor and actually caused quite a bit of damage for previous owners who apparently weren't paying attention to this. I just lay a washcloth there to stop anything from running out onto the floor.

Much as I don't exactly care for glass doors in a tub/shower combo I think I am going to go with a hinged glass screen when I remodel. It goes about half way across so no glass and no track on about half the tub.

I just read about these things on Amazon this morning. I do not know if this will serve your purpose.

http://www.amazon.com/gp/product/B001A0NA7E/ref=s9_simh_gw_p364_i1?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=center-2&pf_rd_r=1F4DH9XE2FX8KV2GKN17&pf_rd_t=101&pf_rd_p=470938631&pf_rd_i=507846

The only thing I've found that works is a heavyweight curtain/liner. The magnets are too weak to ever stick, and there's usually nothing magnetic down there - at least where I live, fiberglass and acrylic tubs are more common than cast iron or metal.

I'm going to ask the contractor/tiler if he can run the shower's floor curb up the walls, in effect giving me a wide doorway with sort of a jamb on each side. That will give me a little side wall to put the curtain behind.