I feel that magnetism is a relatively under-explored avenue for magic, despite the existence of quite a few spells dealing specifically with the manipulation of metal. As such, I've written up a couple of spells dealing with magnetism.
Lodestone, a 1st level spell, turns a small stone or metal object into a magnet. This can have a number of mundane uses - such as creating an impromptu compass - or combat uses, like magnetizing an arrow head so it strikes just a little harder against an armoured enemy, or sticking a magnetic rock on your opponent's sword to throw off its balance. More importantly, a low-level magnetism spell allows players a chance to mess around with magnet magic early in the game and get a feel for how to creatively use magnetism, thus setting the stage for later spells.
Lesser magnetism allows you to turn a chunk of rock or metal into a powerful magnet, or magnetize a single metal item. As an added bonus, casting it again will reverse the polarity of the magnet. This allows for great versatility with a single spell and opens the door for many creative uses. Casting it on the floor will pull armoured characters to the ground, casting it on the ceiling will yank them off their feet. Touch a guard and watch as he struggles against his own armour. Cast it on your weapon to give it that extra momentum against enemies - but watch out or your weapon will get stuck to their breastplate. Being pursued by enemies down a narrow cliffside path? Cast it twice on the cliff face and watch as they are repelled into thin air.
Greater Magnetism has a longer duration and the added functionality of being a ranged, area-effect spell. Now you can magnetize your whole party's weapons with one spell, or blast a formation of guards and watch them hilariously struggle to walk as their full plate sticks to itself.
Since there is so much possibility with these spells, I have tried to include as much detail as possible in the spell descriptions to aid players and GMs in their use. Even so, much of the effects are likely to be context-specific, and will require GM adjudication (for instance, casting lesser magnetism on a horse's barding armour will not slow its movement speed, but may grant its rider a bonus to checks made to remain in the saddle).
The OGL, PFSRD-compatible spells are available after the jump:
