Viral has written an interesting post looking at how some large (traditional) organisations are afraid that their employees will waste time unless access to all social networking sites & Instant Messaging is/are banned - the BBC wrote a piece on the very subject.
It's soooo old school to judge the value of your employees by how much time they spend at a desk - measure their results and let them get on with what's important. I personally find social networking sites to be USEFUL for my work but I understand that's not necessarily the case for everyone.
Remember when such companies banned Internet access all together citing the same fear that people would waste time surfing the web when they should be working. I use the web to BE productive @ work as I'm sure many of you do too.
I can waste time without any technology - give me a window. I can watch the birdies / clouds / rain!
If I'm not important enough for a view of the outside World then no matter - I can look busy and still do absolutely nothing useful. I can think of all kinds of interesting things whilst tapping away at my keyboard and staring (into space) at my computer screen. I can send pointless emails to my peers to appear busy - sending "I'm still here messages" (or "keep alive packets" as James calls them) to those around me.
OR I can be left alone to get on with exceeding my work commitments! I work when I am most productive FROM WHERE I am most productive USING THE TOOLS that make me most productive thereby achieving a sensible work life balance as MY EMPLOYER TRUSTS ME. I've never worked so hard in my life, I'm not earning the most I've ever earned and yet I'm really happy.