Have you recently updated to the iPhone 4 or the Droid X? If so, and you had an earlier version of smartphone before, check out some interesting uses for the old phone. Of course if none of these uses suits you, you have many recycling options for your old electronics.

• Remote Control: there are plenty of free applications on both Apple’s App Store and the Android Marketplace for remote control capability. You could use your old smartphone solely for that purpose.
• Portable Audio: if you don’t have an iPod, you can use your old smartphone as a portable audio device (so you don’t have to utilize the phone you’re currently using as a phone). MakeUseOf suggests setting the phone’s profile to flight mode, disabling the Bluetooth and dimming the backlight to maintain battery life for as long as possible.

Find more ideas over at MakeUseof’s 5 Interesting Uses For A Spare Old Smartphone.