Twitter is a really great tool for your personal CPD and inset needs. How often do you feel like you could benefit from a course but there is no time or money for you to be released?
Using twitter in the right way can have a massive impact on this. All you need are the right contacts to start you off and you create your own staff room.
I have complied a list of people that are really useful to follow, all are helpful some are subject specific. Once you follow them you can see what they are saying or get links to really good articles they have written.
The best bit about twitter is that you can just ask questions and get many responses from all over the world helping you develop your practice.

@ictevangelist. ICT teacher
@syded06. PE teacher
@tomboulter teaching and learning
@dvplearning teaching and learning. Solo taxonomy
@dockers_hoops. English teacher
@biomadhatter. Science teacher
@totallywired77. Solo taxonomy
@edujen. ICT in education
@tesscience. Science resources
@gavinsmart. ICT and e-learning
@elkel99. MFL teacher
@misskmcd. ICT and business
@mrwickenspe. PE, geography and SEN
Apologies for missing off do many good practitioners but this will just get you started, check who they are following and follow them too.

Another useful tool is following groups by using #s
#ukedchat and #dlchat are 2 really good examples of organised groups that have structured sessions on specific topics.