If you are still nostalgic about the days when you listened to your "ghetto blaster" then the Berlin Boombox should probably be high up on your Christmas list.It's available from Firebox.com and we've been playing with the retro speaker dock for your phone, to see if it's worth the bother.The portable, monochrome speaker is battery powered (two AA batteries), comes with two speakers, and a simple volume knob to crack up the noise. Oh, and it's made out of cardboard, did we not mention that?Created by German designer Axel Pfaender, using industrial-strength recycled cardboard, the speaker arrives flatpacked for you to assemble.Don't panic - your origami skills don't actually have to be that good, and although our test unit came pre-built, we were able to re-flatpack it and build it again with ease.Once you've built your Boombox you can then connect your phone. Rather than work with a specific smartphone, you can connect any device that takes a 3.5mm headphone cable. It is worth pointing out that bigger handsets won't fit in the available slot. The Nokia Lumia 920 and the Samsung Galaxy S3, for example, don't - they are too wide.As for the sound, it's not great, but not too shabby either considering the power output on offer and that it is running from just two AA batteries - there is no plug into the wall option.\u00a0Ultimately the Berlin Boombox is a bit of fun. At \u00a350 it is more than likely to be a bit too pricey to be worth considering however, after that initial giggle you'll have making it and showing it to your mates. But it will certainly get heads turning, and make for a great picnic accessory when the sun comes back next summer.