When you cast the mass version of the cure light wounds spell, its range changes from touch to close and from creature touched to creature touched/level with targets within 30 feet of each other. To this sounds like a ray spell as you would have to make an attack roll vs every creature (this is because you could target undead and living creatures with the same casting). Is it possible to have the same creature targeted by the spell more than once? I dont see any place which states you can only affect a creature once with the casting.
Update:
Since there has been debate over how the rules should be applied in this case, lets do a comparison with out multiple touch spells.
- Cure Wounds mass spells "Target one creature/level, no two of which can be more than 30 ft. apart"
- Chill Touch "Targets creature or creatures touched (up to one/level)"
- Haste "Targets one creature/level, no two of which can be more than 30 ft. apart"
- Bull's Strength mass "Targets one creature/level, no two of which can be more than 30 ft. apart"
- Cat's Grace mass - "Targets one creature/level, no two of which can be more than 30 ft. apart"
Since I dont know of anyone who can successfully claim that Chill Touch cant be applied to the same target multiple times in a round assuming a sufficient bab or hasted. Someone can be affected by multiple haste spells, but only one has the effect, and is not helpful doubling up in this case because its part of the same spell so any effect that would dispel or counter one would get all instances of it. Same with Bulls and Cats. The most important difference is that the others except for Chill Touch say "One creature" but that can be thought of in two ways. The one likely intended being that a creature can only be selected once for the spell, or the creature can be selected multiple times each time taking up one of the creature targets.