I also use a spreadsheet to keep track of my wins. I post the date I won, the date it was rec'd, ARV, expiration (if there is one) and a link to the sweeps &/or the rules.This comes in handy for when a prize doesn't arrive. I also retain any winning notifications or correspondance in a "prizes won" folder in my email box. I can then forward my notification to them to prove my win, if necessary. (It has helped me get my prize more than once!)
Since about 20% of my wins come from non-ST sweeps/methods, I have to keep a log separate from this site/my profile. The main page/sheet on my spreadsheet is for wins from all sweepstakes, the second page/sheet is for ST only wins... since I needed to keep track in order to join the 10k Club. 
Total won from ALL sweepstakes since January 2007: $30,514.85
ST 2008 Wins: $4,503.70
ST 2009 Wins: $13,393.63
2009 ST wins worth $50 or more:
Live Nation Concert Pack ($75) - six (6) songs and two general admission/lawn tickets for a show
Wii Console & wii fit ($500) - Metamucil
Canon Digital Camera (ARV $300) - Rockport IWG
One month supply of Pampers: 4 coupons for FREE jumbo packs ($58)
$100 cash - Reader's Digest Mini sweeps
$1000 e-certificate to David's Bridal
$5,000 towards a trip for two to Alaska - Trail Mix Crunch Taste of Adventure Sweepstakes (we did a 10-day Celebrity CruiseTour!!)
$100 iTunes gift card - Sunny D Smooth Sailing first prize
Bose Headphones ($162) - Coors Light/Black Music Month
Reese's Peanut Butter Cup Foam Head ($50) - Reese's Are You The Perfect Fan Sweepstakes first prize
$1000 Visa Gift Card & $50 McDonald's Arch Card - McCafe Your Day weekly winner
Official Canadian Football League Football and One World Sports Hat ($120)
iPod Touch 16GB ($299) - Trident gum A Little Piece of Happy™ Sweepstakes Sponsored by Premiere (grand prize)
NCAA Football 10 video game from EA SPORTS ($59.99) - Coca-Cola and NCAA Football Big Score Promotion
Flip Video Camera ($149) - Little Debbie's Miles of Smiles daily giveaway
Asics Gel Nimbus II running shoes ($125) - CONDE NAST & SELF MAGAZINE - 30TH ANNIV. SWEEPS.
Nintendo Wii game system and Wii Sports Resort game ($330) - Papa John's Wii Sports Resort™ Sweepstakes
Trip for two to Las Vegas, Aria Hotel stay/dinner/spa treatments, VIP tickets to Viva ELVIS™ by Cirque du Soleil®, Ventura Elvis Anniversary Collection watch, Sony Music Elvis CD/DVD collection ($3,020) - Sirius XM Radio's "The Elvis 75 Sweepstakes"
2010 ST Wins so far: $368.24
2010 ST wins worth $50 or more:
2 - Viper 787 Electronic Dartboard (ARV $99.99 ea.) - Charter Communications' Daily Deal Sweepstakes
Adidas Shooting Star Men's shoes ($75) - 12 Days of TAF Sweepstakes
NCAA Football 10 video game from EA SPORTS ($59.99) - Coca-Cola and NCAA Football Big Score Promotion (2nd chance drawing win)