I've got an Epson 1295+ Perfection very simple scanner. It comes with a 35mm film or slide "shoe" device which back lights the target slide. From then on it is scanner technology that does its thing. I've found it to very effective if the colours are not too dense or too dark. It can also take a negative balck/white or even colour neg and can inveret the image to a positive one. it is then a case of saving in one of the usual graphics flavours that takes your fancy.
The Epson is very effective and in the UK are reasonably priced. However depending on how much of this work you are going to do now and in the future, ask your friendly corner Camera Shoppe for a quote for batch activity and so on. And of course you can get this work done and "posted" to your web site or emailed to you etc etc.
There maybe a backlight shoe available for some cammies - or have I invented another give away. Hey ho....
I suppose if push came to shove you could always go '50s and project the image onto the wall and take a cammy shot of it.... only a thought.
Or you could get lucky and find a friend of a friend who's willing to lend you a dedicated 35mm scanner! The advantage they have over a general purpose (and much cheaper!) scanner is the ability to handle the colour depth. From my limited experience I'd expect you to need a decent photo-management program to adjust the colour balance and, if you've got cardboard mounts, trim the hairy edges! Expect to spend a long time cleaning the slides too.