This morning I paid £20 for another six months of Pay As You Go mobile internet. In the age of Twitter, Whatsapp, email and Facebook, I see little reason in needing voice and text bundles. I only occasionally top up to send a couple of texts. Granted it is on T-Mobile UK, the network that pissed over their customer base last month, but I can't complain with the price. And with Orange roaming enabled, they are still the best 2G network in terms of coverage.
There is one big catch. First while supporting HSDPA, T-Mobile speeds are capped at 250 Kbps on Pay As You Go, which is barely even EDGE speed. I've complained to a T-Mobile engineer about this, but there was nothing he can do apart from the go contract advice. Still, despite the 500 MB limit, it is fine for Twitter, email, Facebook and browsing via Opera, and you only pay an average of £3.33 a month for data. Besides I have a Three MiFi that I top up during times when I do need the bandwidth.
If you do need voice and text bundles and do not mind going contract, Three UK's SIM 300 tariff on a 12 month contract is a good deal. For £10 a month you get 300 minutes, 3000 texts and 1 GB of internet. If the 12 month contract puts you off (like it does me), the SIM 100 rolling contract offers a bit less (100 minutes, same amount of data and texts) for £10 a month.
Three does (did?) have a £5 a month SIM only contract purely for mobile internet users, including 5000 minutes of Skype-to-Skype calls. Unfortunately the deal is buried deep on their site (if it is still there). I do know the tariff existed in some form, but you may need to ask one of their sales store as I can't find it on their site.
Obviously if you are a big data user like some of my twitter friends are (who regularly use 1 GB a day!) you can always go all you can eat with Three's The One Plan. £25 a month for 12 months, gets you unlimited data goodness to consume. And unlike most networks, tethering is allowed.