In my vision, a DFRPG Technomancer would have one 'drawback', namely that all his spells/rituals would require focus items to use. He wants to lob a globe of fire? He builds a 'gun' that can do just that as evocation. (Focus item, +1 offensive Fire) It would need some fleshing out, as it needs to be balanced, but it seems to me that this could make a very interesting character type. As an obvious advantage, he might be able to 'psychically' contact computers with Spirit magic.
An other effect of such a build, would be that his gadgets, are essentially focus items/potions/enchanted items and thus immediately immune to hexing by others. A form of Sponsored Magic would allow him to magic about electronics without blasting them apart, while limiting his own spellcasting by requiring focus items. A quick thought about this and I would say, keep all the costs the same (-3 for Thaumaturgy and/or Evocation, -2 for Sponsored Magic), but give him a few more Focus Item slots. To balance it out, perhaps let him start without any specialization bonuses.
Or am I unbalancing things too much and thinking too far out of the box? :p