Simulate IR with Photoshop.  Works on scenery photos that are exposed for bright foliage and deep blue skies (i.e., use a polarizer filter).

Note files were created using Photoshop v 7, and are untested with previous versions.

1) dump all *.ahu, *.cha files into a folder that will be accessible when running photoshop
2) load photoshop, and open image
3) open the "adjust HSL" dialogue (Ctrl-U)
4) load the "simulate_color_IR.ahu" or simulate_BW_IR.ahu and apply it
5) open channel mixer (Image->Adjust->Channel Mixer)
6) load the "simulate_color_IR.cha" or simulate_BW_IR.cha and apply it
7) for BW IR, go to your favorite BW method (greyscale or channel mixer-monochrome)
8) for color, channel shift IR, reopen the "adjust HSL" (Ctrl-U)
9) load the "channelshiftIR.ahu" or channelshiftIR2.ahu file and adjust the channels to your liking
10) adjust levels to liking

It isn't perfect and certainly isn't absolutely realistic.  The idea is based on the fact that the RGB filters over the CCD have seconday bandpasses in the IR, and each is affected by different wavelengths.  
The first HSL adjustment shifts visible wavelengths around to mimic the RGB filter IR response to some degree.  The channel mix step swaps colors (because that's what happens in the filter IR response too).  The last HSL adjustment was found by trial and error to mimic channel shifted IR imagery.

Good luck. 