If you have a huge stack of old negatives or slides, your best bet is to send them off to India. Seriously: there are services which will scan all your negs, let you choose which ones you actually want to keep via a web browser and then get the digital files returned to you. Apparently it’s pretty cheap.
Or you could do it yourself, with the iPICS2GO Negative to iPhone Scanner. It’s a black box which uses your iPhone 4/S’s camera to snap photos of your own old film and then feeds them into software to produce the photos