(It has been a while, this is basically from memory). I think the IRDA
SIR receivers do more than just pass on the pulse as logic levels, at least
they are more expensive so Id expect them to do more :-)

The shark IR was designed for TV remote use, the bandpass filter on the
38kHz receiver seemed like it would do ok on the other popular 36kHz and
40kHz TV remote modulations. (And of course nothing to do with the frequency
of my IR keyboard :-) The TWIRP people thought that it should be ok with
their two way IR protocol too, though we never finalised and got code.

The NatSemi IR front end comes with the eval kits for several of their
Super I/O chips (in the shark case the PC87307EB). It comes with a few pages=
 of documentation with the
schematics of the module and various example IR circuits. It has a number
on the document 420-521675-002.

If you use a different IRDA module, note that the HP ones tend to have
two RX lines and need a little more work. The Temic ones are probably ok.

Mark