All of these come recommended by us, so you know they'll perform brilliantly. They all pack wireless Bluetooth connectivity too, and at least a few hours of battery life. Some even allow you to top up your phone's battery if you're running low on juice.
Don't be tied to a power point, take your music with you with one of these portable speakers. We've got ones for all budgets, from around £50 to £400-ish.