Best source to set your watch from ?.

[airchitect]

Cell

[wmoore]

I use the TRF clock, I'm here everyday anyway, but I did check it against other sources and its certainly close enough for those of us living in a - 4 + 6 mechanical world.

[DJJon]

Apparently the TRF clock is just your computer's time so not a good source.

I like http://time.is on my mobile devices because no need for Adobe Flash and it runs continuously.

[Htab]

My iPhone

[dfjaws]

I use time.gov

There's a free app for it too for iPhone/iwhateverelse users if you wanted to see the time in an iOS device.

[How]

www.timeanddate.com

[Andad]

My Seiko Astron.

Sits on my bedside table quietly solar charging and syncing itself automatically every day to one of the many passing satellites.
Amazing technology IMO.

[Fredrik]

I have all my computers synchronized via NTP so they are always within a few milliseconds. Very convenient. This can be done regardless of OS.

[Time2time]

Dialling 123.
My mobile.
TV guide.

[SALTY]

For me, the exact time is not as important as the watch's ability to keep time. So, I will, upon retriving the next in-rotation piece, set it to either my radio controlled Skyhawk or my iphone then always compare it as against the standard upon which it was set. Both my cell phone and the quartz Skyhawk are accurate enough for my uses and, again - for my purposes, good enough to check the accuracy of a mechanical watch over the course fo a few days or weeks.

[CLRBLULITE]

Samsung Galaxy S3 via Verizon.