> http://www.pond.ie/ftp/stamp1_apps/ircomms.pdf

In addition to what Andrew has said, the circuit I always use

http://home.clear.net.nz/pages/joecolquitt/txless.html

IMHO transistors like the 2N2222 (as used in the Stamp
example above) are crap for IR transmission. They can't
switch high LED current fast or cleanly enough. ZTX types
are far far better. If possible you could add a reflector with
the LED(s) pointing backwards into the reflector. Also, if
you can get your hands on one from a dead VCR or TCV,
those sealed can receivers are excellent for response at
distance and for wide-angle coverage (eg wall-bouncing).
The IS1U60-types are OK within a fairly narrow beam.
Immunity to ambient can be improved by adding an extra
filter (eg exposed film, perhaps a blank frame from a roll
of negatives - dark dark purple) and making the receiver
pick up the beam through a shortish tube

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