Programmers Calculator is built for programmers, allowing for base conversion among other things.

<a href="http://m.netninja.com/calc/" title="Programmers Calculator for iPhone" target="_blank"><img src="http://www.modmyi.com/images/apps/programmerscalc.png" border="0" height="354" width="320" /></a>

<a href="http://m.netninja.com/calc/" title="Programmers Calculator for iPhone" target="_blank">http://m.netninja.com/calc/</a>