Groupon offers the JLab Crasher Portable Bluetooth Speaker in Black/Gunmetal (pictured) or Sport Yellow/Gray for $39.99 with free shipping. That's the lowest total price we could find by $10, although we saw it in April for $10 less. It features a speaker phone, full-size USB port for charging smartphones or tablets, wireless music streaming via Bluetooth, AUX cable, and up to 18 hours of use on one charge.