I work full time but am wanting to supplement my income by doing some additional work from home. I am highly qualified - up to masters level and considered stuff like exam marking (unfortunately am not a teacher so that's out), e-learning tutor? web content writer?
Does anyone have any (realistic and legal!) other ideas or advice on agencies and employers?
Yes to both, also try adult teaching / evening classes - you do not always need a specific teaching qualification to do this and it can be very rewarding as well as paying a bit. I did WEA (workers educational association) for years, and in addition local authorities are often looking for part time tutors.