This shows the (upgraded) HP 260 G1 mounted on the back of a 24" monitor via a 100mm VESA mounting. The hardware used to mount the HP 260 is a two part mount, one piece fits to the monitor, the other, which slots into the first, fits to the VESA mounting on the bottom of the HP 260. I used this kit : http://www.amazon.co.uk/gp/product/B000NVR978 (Allcam LCD110 LCD TV Wall Mount Bracket Slim Slide In VESA 100x100).

Note: Despite some of the images on the Amazon product page showing both parts as having holes for a 100mm VESA mounting, actually only one side did and I had to drill the other with 4 holes to mount it.

Note 2: The cable wrapped around the mount is a DisplayPort to DVI - normally you'd use a short 25-30cm cable to connect from the HP 260 to the monitor, but I already had a 2m one to hand so used that.