Adding noise to tilemap

[WildFactor]

Hi!
We love 2Dtoolkit, and we are doing our second game with it. (http://www.wildfactor.net/ )
We are using the tilemap heavily

We are doing an horror movie game:
http://www.machiavillain.com/

Nothing is right and parallele in our world
But we want to make the tilemap less clean, by adding noise on the vertex position.

Where is the best place to do this in the code to insert a noise function on vertex position  ?

Thanks.