1999 Honda Accord Cuts Off While Driving

99 Acord 4 cyl cuts off while driving, may start up immediately or take up to 5 minutes. Can go long periods without a problem and then it starts again.

have fuel pump relay checked. Often Hondas have had a problem especially when interior of car is hot after sitting in sun. The relay is under center of dash and easily replaced. The microprinted boards flex under heat and vibration and create and open circuit and then no fuel pump action. Also check pump pressure and return pressure and filter replacement.

Also, besides that PGM-FI Relay, the distributor can be intermittent. Same symptom: sudden stall. Restarts in seconds, or minuets, or hours. The distributor can malfunction at any outside temperature.
Unfortunately, the ignition switch can be intermittent, and have the same symptoms. There is too much current routed through the ignition switch, through ONE contact. If you are in the habit of turning off things (a/c and heater fan, wipers, etc.) with the ignition switch, you hasten the onset of the faulty ignition switch.
It can be tricky determining which component is at fault. The ignition switch is the cheapest part.
Your mechanic can get some pointers here: http://www.tegger.com/hondafaq/faq.html Then, click on the applicable problem.