Microsoft Lync allows you to use public URLs for your profile picture. That’s why I needed it, yours may differ. Either way here is how you get the link to your Pic (which is a public link)
1) Log in to Facebook
2) Click “Profile” top right
3) Right click your profile pic and select ‘properties’ (IE9)
4) Find the URL e.g. https://fbcdn-profile-a.akamaihd.net/hprofile-ak-snc4/2xxxxx_7xxxxxxx31_181Xxx_n.jpg
5) Copy/Paste use as you need.