An inexpensive little application with not just 'cool', but very functional features to power up that Canon DSLR. DSLR.Bot is a highly recommended application download if you already have one of these supported iPhone, iPod Touch, or iPad devices. The ability to DIY an infrared trigger and extend range with a simple stereo cable makes it even more practical to use. To keep consistency with the IR trigger (if you choose to purchase one from DSLRBot.com) it comes with a supplied velcro band that simply holds the IR trigger onto the side of the lens. The next time i'm going out to TimeLapse or try my hand at HDR, this little application is going with me. You can find it on iTunes through the link below.
For more information on all the features, tips, and DIY tutorials on the IR trigger - check out DSLRBot.com.