Freightdog,
In Wisconsin, the Soaring Society of America gives the following sites, and states that each provides instruction, and doesn't require you to be a member. You will need at least 10 instructional flights and 10 solo flights. There is no set hour requirement. Ultimately, it's a matter of proficiency. Plan on between seven hundred and a thousand dollars to add on the rating.
I've also included some links to other areas that offer glider instruction. Right now, your best bet will be to travel and knock it out in a short period, unless you happen to live near an airport where there is much soaring in the winter (Flatland isn't known for it's outstanding soaring in the winter).
There are a number of places in Florida, Arizona, New Mexico, Nevada, and California that offer soaring instruction year-round. I have some links below to a few places. I didn't include the link, but you can easily find some info on Minden, NV, on the web. That place is extremely busy doing glider instruction all the time. You can get cheap accomodations in Reno, nearby. Good luck!!
Hubertus, WI
Wisconsin Soaring Society
Based at Hartford Airport, Hartford, WI, 30 miles northwest of Milwaukee. Week days by prior arrangement. Aero tow only.
Land 'O Lakes, WI
Barry Aviation Inc.
Airplane & Sailplane Rides.
Manitowoc, WI
Magnus Aviation Inc
Located at MTW Manitowoc County Airport - I43 to Hwy 10 East for 2 miles, turn left unto North Rapids Rd. 1 mile turn right onto Menasha Blvd immediately past railorad tracks turn left to airport. The following are availabel at Magnus Aviation: aircraft rental of single engine, motor glider, & tail wheel, aircraft maintenance, hanger & tie-down available. Specialize in aircraft sales & leasing of Cessan, Diamond, American Champion & Stemme. Aircraft include: Motor Glider, C172, C182, & Champ.
Sheboygan Falls, WI
Magnus Aviation Inc
Located at SBM Sheboygan County Memorial Airport - I43 to Hwy 23 West, 6 miles to Cty TT, North 1 mile to airport.
The following are available at Magnus Aviation: Flight & ground instruction, aircraft maintenance, charter services, hanger, & tie-down, twin-engine and tail wheel instruction, glider and seaplane ratings. Specialize in aircraft sales and leasing of Cessna, Diamond, American Champion & Stemme. Aircraft: Motor Gilder, Champ, C172, C182, Aztec, Seaplane - Amphib.
Sturtevant, WI
Sylvania Soaring Adventures
South on I-94 to Exit 333 (Wisc Route 20)West on Route 20 to Sylvania Ave. (west Frontage Road), south on Sylvania Ave. 1 1/2 miles to Sylvania Airport.
http://www.thuntek.net/~sundance/ratings.htm
http://www.soarfl.com/glider_add-on.htm
http://www.serioussports.com/seminolelake/
http://www.crazycreekgliders.com/rates.html
http://home.att.net/~flyace/Advtng.htm
http://www.flyingmag.com/Safety/ArticleDisplay.asp?ArticleID=46&page=3
http://www.turfsoaring.com/lessons.html
http://www.jccn.iowa-city.ia.us/~bhawk/club/rates.html
http://www.gg-pilot.com/airmancert.htm
http://www.milehighgliding.com/instruction_CO.htm
http://www.skysailing.com/pages/lessons.html
http://skykingsoaring.com/
http://www.gliderrides.com/schoolG.htm
http://www.kutztownair.com/power.html
http://www.5c1.net/SASSi TRAINING SYLLABUS for TRANSITION PILOTS.htm