a) You can't get ISE to automatically preconfigure your onboard SRAM - but you can of course manually make your design initialize it at startup (although this will require the data to be present somewhere else in the system, which basically defeats the purpose).
b) Create a blockram, and assign a .coe file with the desired contents to it, or use initialization attributes to describe the contents. You can read more about this for instance in Chapter 4 of the Spartan 3 user guide (UG331).
c) Only other idea I can think of right now (early saturday morning after company-party yesterday;) is the retro-way of using a dual-inline EEPROM (or similar) and an EEPROM burner. Program the chip from your computer, and then mount it in your design.