Try Musical Instrument Shops near Oxford Street:
The area around Oxford Street has some really good shops selling musical instruments. Following are the shops where you would definitely find a Vuvuzela:
1- Westend DJ has a good collection. The store is located at 12 Hanway Street.
2- Hank's Guitar Shop is another business providing high quality musical instruments. It’s situated at 24 Denmark Street.
3- You may also find Vuvuzela at Ivor Mairants Musicentre which is at 56 Rathbone Place.
4- Do check out Acoustic Room located at 16 Manette Street too for BuzzzZZZZZZ.
Check out Musical Instrument Shops near Baker Street:
Baker Street doesn’t have that many music shops in nearby area, however there’re some places where you can certainly buy a Vuvuzela. These places are:
1- Howarth located at 31-35 Chiltern Street.
2- The Early Music Shop situated at The London Recorder Centre, 34 Chiltern Street.
Look into Local Gift Shops During Olympic Games:
In the season of Olympics, Vuvuzela is available at many stores, especially the gift shops where the businesses want to boost sales during peak event period. Also try looking for the horn in big supermarkets like Tesco Brixton, Sainsbury's etc.
Buy Vuvuzela Online:
You can also take help from the online shopping website and place your order for a Vuvuzela. Visit the websites mentioned below and buy a horn of your favorite color.
eBay.co.uk is a place where you can always buy one instantly and it'll be delivered right on your doorstep. Check latest Vuvuzela listing at eBay.
If you're a big group and want to have BuzzZZZZ for all group members, try Alibaba.com and DHGate.com and save money of bulk order!
As mayor of London is still undecided, whether to allow Vuvuzela or not in games, the official online store f 2012 London Olympics, i.e. shop.london2012.com doesn't have it. Do keep and eye on the store too, as it will definitely have one if it's allowed officially!