turn your iPhone into an SPL meter with ‘Studio Six Digital’s’ applications.
Software to use your iPhone as a wifi hotspot: http://www.junefabrics.com/iphone/index.php
http://sciphoneapps.com
An alternate to browsing software in itunes: http://www.appshopper.com
http://www.iphoneappstore.us
http://www.jaadurdp.com
An app to get email alerts on your iPhone: http://www.intelliborn.com (look for myProfiles)