Silicon7 makes (made?) Pseudo SRAM, which is a DRAM that's pin-compatible as SRAM. I.e., you don't need a separate DRAM controller. Here is the block diagram. I think this is cool; it evidently has the ease-of-use of SRAM but with just 1T DRAM transistors. (memory cell)
Somehow this company's existence escaped me, which is even more ironic given that their CEO was my advisor in grad school before I retreated from VLSI. Does anyone know the status of the company?