Pool getwork "target"? In a getwork request, bitcoind sends a target corresponding to the current block's bits value. Do the major pools send the same target as one would expect from bitcoind, difficulty of "1" target, or perhaps something else?
Most pools define their target value (minimum value required to earn a "share"), as:

T = 2 ** (256 - 32) - 1
= 0x00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff


The Bitcoin protocol defines a difficulty of 1 as a target of:

D = 0xffff * 2**208
= 0x00000000ffff0000000000000000000000000000000000000000000000000000


They are nearly equal:

T/D = 1.0000152590218967


The precise target used for earning shares could be set to a larger number, but that would increase the number of getwork requests sent to the server as shares would be easier to find.  Note that if you decrease the size of target, you would reduce the probability of finding ANY valid shares for a given block header (unless you allow changing the timestamp as well as the nonce).  As it stands, the expected number of shares found per getwork request is approximately 1 (when the target has 32 leading zero bits).