I'm not looking to take shortcuts and put safety at risk, Currently
half of the outlets are the older 2 prong variety (all in
kitchen/bath/livingroom are updated). We just have a few outlets in
hall ways and bedrooms that are older 2 prong still. the only devices
that get plugged into these are 2 prong devices likes vacuum, and the
laptops which are three prong (using an adaptor). We're repainting the
hallways and I was going to upgrade these outlets more for looks now
(to white outlets) and when money is less tight have them grounded.
I'm just wondering if there is risk (ie fire, etc) due to hooking 3
prong outlets to ungrounded box.

We plan on grounding eventually. How big a job is this for experienced
electrician? The outlets are all on 1st floor of a ranch and the
finished basement below has suspended ceilings (ie access to flooring
above by moving tiles).