I'd like to encourage all direct male Cooksey descendants to consider getting their Y-DNA test done. We've been using Family Tree DNA (www.familytreedna.com) under the British Isles study group (substantial savings if you join a group, unfortunately presently there is not a Cooksey Surname group). Some comparison's on a few testing services:
http://www.isogg.org/ydnachart.htm
(note ancestry.com just started one up just very recently, look under the "DNA" tab)
Results come back in 6-8 weeks.

If you're descended from Samuel Cooksey, Planter, of Charles County Maryland (d: ca. 1708/9) and not in a rush, (don't mind waiting 8 months, without directly "seeing" results, you can only infer by looking at the data) you can use smgf.org (Sorenson Molecular Genealogy Foundation) which will test you for free(!) if you donate a 4 generation pedigree chart. The way you use this is by matching to someone in the database, and we have two descendants of two branches of Samuel Cooksey that match already. So if you have a direct lineage that you want validated to Samuel, you can put in one of my links, and if your pedigree fits in (it shows it if you provide access, which you must if you want to try this route), you can be pretty sure your paper genealogy is correct (at least to some level of certainty within x generations of Samuel, which is dependent on the closeness of the fit).