Re: Unusual pickup combinations...
On an old scalloped 70's Strat, I installed a Hot Rail in the bridge, a Dimarzio/Jem HS-2 in the middle and an HS-3 in the neck... The HS-2 is out of phase with the HS-3 resulting in a nice Brain May tone in the 4th position when using gain. The second position results in a punchy Dire Straits sound. The HS-2 is hooked up to a tone pot that 's used to turn off one of the coils for single coil mode (though I may change that and hook up the HS-3 instead) I intend to wire the Hot Rail in series/parallel.
On another old Strat, an HS-3 and HS-2 in the bridge and neck respectively is hooked up to a push/pull pot to split the coils. An old Squier single coil (large ceramic magent) is in the middle for some nice Tele/Strat tones.
And in an old Squier, a '74 Strat pickup in the bridge and a '79 pickup up in the neck with a Squier RWRP pickup in the middle--very unique but vintage tones (Beatles, Knopfler, Hendrix...)
Hope that helps.