projections and raster maps

What is the best way to change the projection of a raster layer (eg ll to
utm).
I know that it can be done using the imagery functions, i.rectify, etc,
with judicious intervention of m.ll2u, etc, on the POINTS file,
but this seems like a crude instrument considering the equations are known!
From my brief scan of the manuals there is an [a-z].proj for everything except
r ...

Suggestions anyone?

Thanks

Simon Cox

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        Dr Simon Cox
         __ L
      ,~' L_|\ Department of Earth Sciences
   ,-' \ Monash University
   ( \ Clayton Vic 3168 Australia
   \ ___ /
    L,~' "\_x/ Phone +61 3 565 5762
              u Fax +61 3 565 5062
        simon@cerberus.earth.monash.edu.au
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