Ever been to a picnic where the beers are warm? Of course you have. Have you ever, though, suffered the turmoil of a beerless outdoor feast without tunes to pass the time? If the answer is yes, you’ll understand the existence of Ultimate Rager. Disguised as a dull-grey rucksack, this Kickstarter project (from US$59) houses both a 15W Bluetooth speaker system and a cooler pocket with capacity for twelve frosty ones. There’s even a mic-in port for intoxicated karaoke on the go, while the battery (good for 8 hours of park partying) can charge your smartphone. Oh, and it’ll carry your miscellaneous picnic bits, too.