There is a good bit in Tim Ferriss's "4 Hour Work Week" where his voicemail tells people to email him, and he will only check his email once per day, in the morning, IIRC.

Yeah, Google Voice should add that feature. Or you could build it pretty easily with Twilio.

Google Voice does come with call screening: http://www.google.com/googlevoice/about.html

Which I've used, but it's a PITA rather than any real aid, especially w/o an Android phone. It also slows down and mildly annoys anyone who is calling you (maybe not a bad thing, but certainly not the same thing). And it's only really useful for people not in your contacts list, which is probably significantly less than 1/2 if you're not using it for work.

Plus, anyone not annoyed enough will still make your phone ring every time they call, demanding attention now to at least see who called. But I could do that before, with caller ID.

You could build a small app to do this with twillio. Patrick did:

http://www.kalzumeus.com/2009/12/29/twilio-phone-call-web-ap...

http://www.kalzumeus.com/2010/01/15/deploying-sinatra-on-ubu...