Using FPGAs to implement reconfigurable DSP architectures?

SRAM based FPGAs are commonly used for rapid prototyping and hardware emulation, as well as for the `mopping up´ of `glue logic´ and the customisation of mass produced hardware. A less common application of FPGAs is in the area of computation. This is, perhaps, because the limited capacity of the FPGAs, unless used in very large numbers (as in the case of some commercially available hardware emulators), seems to exclude the implementation of the complex hardware units (floating point units, etc.) often associated with computation. However, the situation is not this bleak because there is a large class of so called generalised cellular automata problems that can be profitably tackled using custom hardware constructed using FPGAs