I have donated the Hopsox pattern to Médecins Sans Frontières as part of the p/hop project.
MSF is an independent humanitarian medical aid organisation, committed to providing medical aid wherever it is needed, regardless of race, religion, politics or gender. We currently work in over 60 countries helping victims of war, natural disasters, disease epidemics and those who simply have no access to even basic healthcare. For more info, please visit www.msf.org.uk
For more information about p/hop and how to donate see here
I have knitted two pairs of Hopsox. For the first pair I used Yarn Yard Bonny with 2.5mm needles, and for the second pair, Dream in Colour Smooshy with 2.75mm needles.