This article by Rhymer Rigby published in the Financial Times gives a few examples of companies (like LRN, Wandisco, Evernote, Netflix, Redfrog, Inbucon). She states (a bit quickly?) that limitless holiday is prevalent among technology businesses but not limited to them... What about no paid holiday? If you read French, there is a post on Rue89 that interviews a little more some of the firms.
A more balanced account in the Huffington Post while for Business Week, only 3% of US companies would have adopted what HR specialists call a ROWE system (Results Only Work Environment).