Pretty powerful I agree. In effect you can interconnect 2-D tables to form relational databases. A very basic and necessary function in the database world.
Another good one is the HLookup function.... does the same thing VLookup, but instead of reading columns, it uses rows. Using them in conjunction is a good tool to know how to use!
You may be interested in PUP from J Walkenbach. He has an impressive set of add in tools for excel for a modest price. The version I have has a VInterpolate and Hinteroplate lookup type function. It will interpolate between a table of values, very usefull to me many times. Here is the link to his web site
Yes, VLOOKUP is a powerful tool but most of excel's other lookup functions are also useful. It can be very helpful to make one lookup fuction an argument of a second fuction (use Match to find the row or column of a chart which in tern is an argument of Index).
I recommend Excel for Scientists and Engineers by William J. Orvis
You can see the entire index at;
Another interesting function that does something similar is the offest command. I use this for dealing with information inputted from drop down menus built using the forms options.