South Carolina has a lot of online archive material to offer, and a lot of places offering it. Spend some time and look around at several intriguing sites.
South Carolina Department of Archives & History is the official state repository with numerous links to online content. The list of Digital Collections is a good starting place, with details of the few collections fully available online, including:
There's also a smallish but lovely group of Collection Curiosities, digital images of odds and ends from the Archive holdings.
For you family history/genealogy types, check out the Online Records Index. This is a terrific name-searching tool that will point you towards offline records for wills, births, land sales, slave holdings, and a whole lot more. Covers the 1600's to the 1970's. A particularly nice touch...the search box automatically list all names that match the first few letters you type. You can find details of the types of records at the Guide to Collections and can search SCArchCat, the full archives catalog, as well.
The archives also maintain a sort of mini-Wayback Machine for state government websites no longer in existence. A few other online resources are:
There's also something called ArchSite, which appears to be a mapping application for historical properties in the state, but truth is, the system is rather poorly described. You have to register in order to use the service here.
Another good resource is the South Carolina Digital Library, a portal of content from schools, libraries, archives, museums, and other institutions throughout the state. This seems to be an active site that frequently adds several types of new content:
Then there's SCIWAY, which sure looks like it's about SCIence, but is actually the SC Information Highway site, and lists a whole lot of Carolina archive activity for both online and offline resources:
SC City and County Archives
That should keep you busy for a while!