Android: Plugging in your phone and mounting the SD card is inconvenient. If you have a rooted Android phone, free app Samba Filesharing will let you browse its SD card right from your computer over Wi-Fi.
Whether you're out and about and you've forgotten your USB cord or you just don't want to be tied down by physical cables, Samba Filesharing is a super easy way to access your phone's SD card from your computer. Just download the app, start it up (make sure to allow it superuser permissions), and type \ANDROID into Windows Explorer (or follow these instructions for Mac OS X). The default username is SDCARD, but you can change the username and add a password from the app's settings. Even if you're unfamiliar with Samba and file sharing, this app is incredibly easy to use, so as long as you've rooted your phone, it's worth checking out. Hit the QR code to give it a look.
Samba Filesharing is a free downlaod for Android devices running 2.1 and above.