Edit: After being completely disgusted about the right shift key location, I searched for key-remapping options.  SharpKeys is a quick-and-easy solution for Windoze 2000/XP/7/8.  Make sure you download it from the author's website as the first two installers I downloaded (from sites I had considered trustworthy) were full of bloatware.  Once installed, I swapped the mapping of the up-arrow and right shift keys on my K400 and wow what a difference.  I'm actually pretty happy with this keyboard after this fix.  I would increase the rating to 4 stars, but the credit goes to randyrants_dot_com for the software, not Logitech.  The only downside with this fix is that it swaps the keys in the OS, so if you plug in another keyboard the up-arrow and right shift will be swapped on that too.  And if you VNC or Remote Desktop you will likely experience the same problem there.The only unfortunate thing with this finding is that there are so many reviews of this keyboard it's not likely that many existing owners will see this fix.Original Review:The K400 is a decent wireless keyboard.  The layout is pretty good given the small format.  The tactile feedback is good.  The battery life, so far, has been pretty good.  I've only had the keyboard for 2 months but just discovered the on/off switch, so I'm fairly impressed the battery has lasted this long (although it may also have an auto-off power save feature).  The range is just okay.  The spec indicates > 30', but my couch is just 10' from my PC in my media center and if I'm reclined or have my legs up a bit it tends to block the transmission.  If I have the media cabinet door closed the range is only a few feet at best.Despite these few short comings, this would be a nearly 5-star product save the one fatal flaw -- the location of the right shift key.  If you look at the right shift key on any well-used keyboard you'll generally see a shiny spot on the left side - where most people strike the key.  Logitech, a company which typically puts out some good, smart products, blew this one.  They put the up-arrow key in this location, making a skinny little shift key to the left of the up-arrow.  After two months of use I still up-arrow virtually every time I try to use the left shift key.  It drives me nuts and and is the reason for the 2-star review.  I have no earthly idea what they were thinking, I can only assume they never actually tested it. 

Question: Is it a wireless keyboard?
Answer: After being completely disgusted about