Communities of Practice (CoPs) are seen as a primary vehicle for knowledge sharing across large and disparate organizations. It is therefore expected that technology will play a critical role in enabling global CoPs. The usefulness of Information Technologies (IT) to support CoP activity in two large, but quite different, global organizations is analysed and common themes developed. BHP Billiton is one of the world’s largest diversified resource companies, with a strong industrial heritage and a mix of blue and white collar workers and levels of IT literacy. CSC is one the world’s leading IT service providers, with a highly IT literate staff and a relatively sophisticated IT support environment. Both organizations could be considered early adopters of the CoP concept. This chapter tracks their evolution and the lessons learned along the way. The common themes arising from comparing and contrasting these two experiences mostly reflect the socio-technical challenges faced when enabling CoPs by the use of IT. In both organizations, the adoption of the newer collaborative tools is slower than anticipated, with the tried and tested face-to-face, teleconferencing and e-mail alive and well. The rule of people first, technology second is reinforced in both organizations. Technology adoption was far more successful as a response to CoP demand than a technology push. Where technologies are deployed, the level and degree of support was critical. The commitment of CoPs to a particular tool is fragile and easily lost through inconsistent performance of the technology. As well as facilitating CoPs, IT also plays an important role in developing measures and metrics for supporting CoPs as a value adding business resource. The ability to digitally track CoP activity provides an additional value-adding role for IT. While the usefulness of IT to support CoPs has largely been oversold in the past, BHP Billiton and CSC are two organizations that have persevered and learned from their respective experiences, to the extent that IT is now playing a key role in sustaining healthy and valuable CoP programmes.