YouTube member blkphoto sends in this video test using the Rode SmartLAV while shooting with a Panasonic GH3 [Thanks Larry]. If you jump over to 1:43 in the video you can hear the immediate difference between the recording and the sound from the GH3 internal microphone.
The Rode SmartLav is a microphone that connects directly to an iPod touch, iPhone, or iPad. You can download a free version of the Rode Rec app to adjust sound levels and with the paid version of the app you can immediately share your recordings to the cloud.
Rode SmartLAV via GearAddix.com
It may not replace your other high end mics and digital recorders, but as you will often hear stories about Lav mics breaking in the middle of a project, it might be handy to keep a Rode SmartLAV around in the kit. Available at the DVEStore.com (found here)
Rode smartLav iOS Lavalier Microphone.
The Rode SmartLAV can also be found via eBay
Rode iPhone iPod iPad SmartLAV - via eBay