From: Alan
Frisbie 
  Harbor Freight sells a nice hydraulic lift table
for under $200 that I
 have found very useful for that sort of thing. It doesn't go up very high
 (like for the top of a rack), but I used it with some wood blocks  
 Thanks for the tip! I got one on sale for about US$140; it's _very_ sturdy.
 And the top is just large enough to hold two milk crates (available at
 Home Depot, BTW), so it's guite easy to build up a stack as high as one
 needs to reach the top of a 6' rack. 
 
Thank you very much for the feedback -- it makes me happy when I
know that someone finds my suggestions useful.
I've used the milk crate technique myself, with a piece of sheet
metal on top to make it easier to slide the load off.  I hope you
secure such a stack tightly.  :-)  I used some of the inexpensive
1" wide Harbor Freight cargo straps.
Alan "You can't have too many clamps or straps" Frisbie