Ending today, Groupon discounts a selection of Masterplug Extension Cord Reels the sizes listed below via coupon code "SALE3". Shipping adds $3.99, but orders of $34.99 or more bag free shipping. Each features an LED power indicator, power switch, current overload protection, and reset button. The deals, with prices after coupon, and $3.99 for shipping unless noted:

• Masterplug Cord Storage Reel (no cord) for $17.99 ($10 off)
• Masterplug 4-Outlet 30-Foot Extension Cord Cassette for $24.29 (pictured, $41 off)
• Masterplug 4-Outlet 40-Foot Extension Cord Case for $26.99 (low by $23)
• Masterplug 4-Outlet 80-Foot Extension with Open Cord Case for $44.99 + $0 s&h (low by $29)

Note that that these are rated for 11 to 12 amps and may not be suitable for power tools and other high-amp applications.