I just ordered a product from Samsung off of their website. Unlike what most reviewers are showing in their demos, this one is a "USB & SD Connection Kit," and it contains 3 things in the box for $29.99: 1) a USB adapter; 2) an SD card adapter, which will allow you to read camera SD cards and such; and 3) a Micro SD adapter, which looks like an SD card with a channel into which to insert a micro sd card.
A saw an ad for the product, and when Best Buy said they didn't have it, I contacted Samsung, who told me to enter h t t p : // bit . ly / oLxmXv
There are some things to note. If you have purchased the USB adapter, and when you plug it in you are getting no response, you may want to try rebooting with the USB device inserted. This was the case with my Samsung Galaxy Tab 10.1 16GB, which I normally have sitting in the keyboard dock. My Tab wouldn't recognize the USB adapter inserted "on the fly," and in fact annoyingly deactivated my keyboard as well. (It is puzzling as to why "on the fly" connection worked for one reviewer on YouTube, who also had the keyboard dock attached.)
After booting with the USB adapter with a flash USB drive ("thumb drive") inserted, my Tab displayed a message down in the tray that the USB device was connected, and instructed me to click there when I wanted to dismount the device "safely."
As is usual from Samsung, there is almost no documentation. Some advice online had me looking under /mnt, and finding nothing. It was frustrating. I had almost given up, when I happened to see a new directory while typing in Quickoffice. It was called "USBStorage," with a subdirectory underneath called "SDA", and under that---finally!---the contents of my Flash drive.
I have also read online that any USB drive you want to view with Android devices must be formatted with FAT32, and not, for example, with NTFS.
Unfortunately, I need to report that there are bugs. First, when I connected the USB adapter on my device "on the fly," it not only didn't work, but also deactivated my keyboard dock. Grrrrrr. Also when, after working with the Flash drive for a while, I clicked for the "safe" dismount, it again deactivated my keyboard dock, forcing me to reboot to regain keyboard function.
The second time I dismounted, the Equalizer app that I have installed for my Music beta suddenly reported that it had unexpectedly stopped working, so I suspect that other hardware on the Tab (headphone jack?) may also have been affected.
Also, from what I have read, devices that draw too much power may require an AC-powered USB hub, rather than a bus-powered one. I have not tried this, but a FAT32-formatted external hard drive, with its own power supply or connected to an AC-powered hub, may be readable with the Galaxy Tab. (The new S2 1 TB external USB hard drives from Samsung, smaller than a playing card and available in multiple colors, are SWEET, but are bus-powered.)
I have yet to do further testing, such as connecting directly to the Tab without the dock, trying out the SD card adapter, or connecting other devices. I have a 1 TB external USB hard drive with AC power, but unfortunately it is formatted for NTFS. I'm uncertain as to whether---if I were to partition a portion of the disk and format it for FAT32 with the Windows Vista Disk Management utility---it would show up. With the number of bugs in the USB adapter, I'm not certain I want to try this, since it houses a lot of important data. But maybe someone else would like to be brave, and report back to us.