Maybe a bit late to the threat but I use Philadelphia Photographics to process my slides. Normally I have 'em just scan them to CD now a days a well and don't even bother with the mounting cutting. They do top notch work, but can be pricey. I'm not sure exact costs but it's super quality work. Give 'em a ring:
Philadelphia Photographics - professional film and digital processing, printing, and imaging services
I'd certainly trust them for irreplaceable stuffs more than Walgreens.
--Grande should be reserved for burritos--