I sit on the OR Society's 'OR in Schools Taskforce' (I was Chair from 2005-2011) which has produced various teaching resources for Decision Maths and OR. Check out our website LearnAboutOR and the award winning careers video (spot the good looking Prof!).
I co-ordinate the Cardiff WIMCS outreach activities, and we have hosted several annual lectures by distinguished speakers, including Johnny Ball and Computer Science For Fun
I've also had the pleasure to meet with Carol Vorderman (twice!), who was awarded an honorary fellowship by Cardiff University, and who sought our advice on areas of policy relating to mathematical education; and more recently was honoured to meet the Minister for Education and Skills, Huw Lewis AM, who sat in my one of my workshops on epidemiology delivered for the Further Maths Support Programme Wales.
Cardiff School of Mathematics is very happy to offer outreach opportunities. This can be a talk on why study Maths and related subjects at University, or general interest talks and workshops. Very happy also for schools to visit us at the University. Do get in touch!
We also host the UKMT Senior Team Challenge (regional final) every November.
Myself and Vince Knight also contribute sessions on mathematical modelling for the Monmouth Science Initiative.
Some of my outreach materials freely available: