Jonathan,
For my own interest I must ask what qualities would you bring to a school or college that they are unlikely to have? That is not a flippant question but the answer may help me understand more about what you would like to do.
There are teaching jobs galore at the moment on
TES - Teaching jobs, resources & ideas from the Times Educational Supplement, most education related jobs get posted on the TES site. There are a few roles on the site at where colleges are looking for people to teach on their teacher training courses, they are full time positions which may go against you but most are open to job share possibilities which may allow you to cherry pick parts of the job spec that suit you.
A few other ideas,
Join a sponsored 'do good' team that travel to schools and offer educational shows.
There are numerous companies that offer inset training days to schools and colleges, thay may be a good resouce to you.
I hope this help, let me know if I can help any more in any way.
Thanks
Matt
Remember,
Those that can.. Teach. Those that can't.... either teach teachers or become management.