First, you should check that your school doesn't have a policy that says instructors must hand out a paper copy of the syllabus to their classes (those policies exist...). Second, you have to think about whether there is anything they need that you can guarantee they've read been handed (e.g., some laboratory students have students sign that they've read the syllabus, for safety reasons). If you don't have to hand out the paper, you should feel confident these days that they can get the syllabus on your class web page.
My current strategy is to forego printing the syllabus for large classes, but to explicitly email the class with a link to the online version (along with a very short introduction). If you want to ensure they get the syllabus, attach it to the email.
For small classes (<20), I have printed out a 1-page "highlights" of the syllabus (my contact info, address for the online version, due dates for assignments, etc.). I may not even do that any more, as I just figure the students are perfectly able to get the information online.
One more thing: on the first day of class, I do go over the important parts of the syllabus, and I also put a copy on the projector as I go over it.