Getting back to defining hokum as a musical genré, rather than defining the word, hokum or "hokum blues" refers to a kind of music usually lumped in with blues music. The stuff I think of as hokum usually has a sense of humor to it, and can be pretty raunchy, what someone once referred to as "single entendré" songs (as in the numbers on "Please Warm My Weiner" mentioned above). Since "hokum" means B.S. or jivin', the songs usually describe ramblin', gamblin', drinking and womanizing (or mannizing?) in a humorous fashion. Some examples:

"That'll Never Happen No More"-Blind Blake (see the thread on this one)
"I Got Mine"-Pink Anderson
"Next Day, Sometime, Not Right Now"-?
"Travellin' Man"
-lots of folks

Some of the classic blues guys (and gals) who did a lot of hokum numbers (as well as more serious blues) were Blind Blake, Pink Anderson, Bo Carter and the Mississippi Sheiks, Memphis Minnie, Ma Rainey and Blind Willie McTell. Modern bluesmen who do re-makes of these classics include Dave Van Ronk, Roy Bookbinder and my favorite D.C. locals, Rick Franklin and Neal Harpe.
There are probably lots of folks at Mudcat that know a hell of a lot more about blues than me and can give more detailed lists of examples and artists, but these are just some of my favorites. And that ain't no hokum!