I am currently doing crew control at my venue. It's corporate AV - so the average technician age is 25 and everyone is generally quite computer savvy - or at least technology savvy. All full time staff are provided with e-mail, the rostering system is avilable over citrix to all staff (so home access is quite easy), all staff are required to have a mobile number registered with work. At the end of each day, I SMS everyone's start times for the next two days, I print out 3 copies of the next two days schedule and pin one to the crew board, one sits on my desk and one sits on my managers desk and I email the schedule to everyone. Guess what - people still turn up late... and when I drag them into my cubicle, they pick up my copy of the schedule and say "I check it on the board yesterday. I must have miss read it."
People like hard copies and people check hard copies... Best bet is to use it to your advantage.