Hi,
Apart from doing an experiment, has anyone got an idea on the pKa of either o/m/p methylanisole?

Cheers

There were some good hits using google with a synonym for methylanisole as methoxytoluene.
The few MSDS I looked at however I didn't see any pKa values.. One of the manufacturers may be able to help.

There's an interesting site for formulas and an estimate of pKa.
http://www.chemaxon.com/demosite/marvin/index.html
Really a neat site with demo sketching an calculations with 3D models.
Nothing beats profound knowledge of running the tests yourself.