I have and old Acer Travelmate 800 LCI that I'd like to convert to a file repository server. The internal 60 GB HDD is too small, so I'm wondering how to find compatible Hard Drives. Is there some site where find compatibility tables and vendors?
Usually HDDs come in 2 dimensions, for laptops and for desktops. So, physical size is not a problem ... you need a HDD for a laptop. Then, older HDDs were IDE, new ones are SATA. This is the BUS type they are using to communicate with the system. I did a search on google for your model of Travelmate, but I've got no detailed description. However if your laptop was made in last 3-4 years, you most probably have a SATA HDD.
In conclusion, you need a Sata Laptop HDD ... and it should work.