The guys at Yireo have produced an excellent addition to their software suite. Vm2Mage works fantastically. I just imported over 1000 categories and over 3000 products from Virtuemart to Magento and it brought all the data accross including the images. This was a lifesaver for me as you can imagine. I had some configuration issues to start with but the guys at Yireo helped out and replied back to my request very quickly. Can't recommend this software enough.