You can select a higher fee if you want. This choice is intentionally limited to a 1x, 2x, and 3x multiplier to avoid leaking too much information via the fee (ie, if you're the only one using a 2.7x fee, your transactions will stick out).
NOTE: from two weeks after the v3 fork, the fees multipliers will change from 1/2/3 to 1/20/166. The simplewallet setting blow is renamed from fee-multiplier to priority, so 1/2/3 are still used in simplewallet, but do not express actual multipliers anymore. The base fee will also decrease by 5 times at the same time.
This behavior is a global setting in simplewallet, and can be changed with:
set fee-multiplier 1 to reset to default, same with 2 and 3.
Miners will select transactions based on decreasing fee per byte, so transactions with a higher fee multiplier will get priority over transactions with lower fee multipliers.
As J Dog says, a glut of transactions in the pool cannot be expected to last long term, as the block size will increase to meet demand.