There are sites like this: Tutor Hunt - Private Tutors & Personal Tutors For Home Tuition
I have never used them so I don't know how effective they are. There's a lot of turnover in individual teacher sites, so there may be a problem with getting traffic and enquiries that way, though some seem to be doing a good job- this guy seems to have carved himself a profitable niche: Home page for Japanese students of English for speech and listening skills. However, few people are charging this much as there's a glut of teachers.
- For Teachers