This are tutorials for photoshop, but you can adapt them to PhotoPaint http://www.macmerc.com/articles/Graphics_Tips/209 http://www.adobetutorialz.com/articles/940/1/The-Pop-Art-Comic-Effect http://www.rnel.net/search/photoshop/comic-tutorials-1
alien skin Snap Art 4 has a comic filter. I use it in CorelDraw and Photopaint. https://store.alienskin.com/products/snap-art-4
Just realized the date of this post... haha
There are a number of tools available online, which helps you to convert your photos into cartoon effects or Comic lookbefunkyfotojet