Does a microSD adapter exist that doesn't stick out of the MacBook Pro SD card slot? I don't want to live in fear of breaking the SD card off while carrying around my laptop.
I know this is an old question but I just found it via a Google search. Check out the Nifty MiniDrive which is exactly what you are describing.
Check out this low profile micro SD card reader for the Raspberry Pi computer: http://www.adafruit.com/products/966
$6 versus $25 for the Kickstarter polished Nifty Drive (I actually bought one for a friend).
I think the Nifty MiniDrive might be exactly what you're looking for:
Are you looking for something like a half-length SD card->microSD adapter? If you want to use that slot, the card is going to stick out--you're probably not allowed to license the SD spec without making the card that size.
However, there are some incredibly small USB drives/card readers that are bigger inside the port than they are outside. This microSD card reader's slot is inside the usb port, and this is a USB drive with a similar form factor.
there are tons of sd/micro sd card readers that usb but they have the same danger. the only alternative is to use a usb extension to plug one of those in, but it still sticks out like any usb cord and can still damage ur usb port. i recommend just sticking to a micro sd to sd adapter and just use caution when using the card