Edit: Thanks Allan1954 - this is even cheaper at Argos, coming in at £19.99!! Argos link here
OK it's only 3G, but surely a decent buy at this price? Amazon reviews look very good.
Comes with 2GB data which lasts 30 days. I'd swap the sim out after the 30 days as top up rates are pricey. Get a sim only deal from Id mobile or Talkmobile or someone else with good rates who support tethering.
BTW you can also buy a 12GB EE sim for £20.99 (at 2GB per month) or a 12GB Three sim which you can use however you want for 12 months. Not sure if it is unlocked, but if it is locked you can unlock these for free by generating your own code (or pay someone £0.99 on eBay to give you the code, keeps them employed I guess).EE 12GB sim linkThree 12GB sim link
Don't forget your 4.4% Topcashback either...wahoo!
-- Blurb --
This clever little pocket sized box acts as your own secure personal hotspot.
You can take it with you and use on up to 5 of your devices at the same time.
So you can find the best local coffee shop, read Trip Advisor reviews and get Instagram and Facebook updates.
Turn it on and off as you stroll.
- Comes with 2GB preloaded data that lasts up to 30 days
- Wireless standards b/g/n
- Transfer speed up to 21Mbps
- WEP, WPA, WPA2 wireless security
- USB 2.0 compatible
-- End of blurb --
Not sure what else to add to be honest. How about some goats in a tree?