I was doing some research on filters and came across this lens to filter size chart on the Tiffen Website. It gives the filter sizes for most of today's popular lenses (I noticed that Tokina lenses are missing) in one chart.
http://tiffen.com/tiffen-filters/lenstofilterchart/
It's easy enough to find the filter size when you have the lens in front of you and you can determine filter sizes of lenses by looking through manufacturer's brochures or websites or on vendor's websites (B&H and Adorama list the filter sizes for the lenses that they carry). But, I haven't seen a chart like this with all the filter sizes in one place. I thought that it might be handy to share...