I pay 3p per text from my phone. Which is already outrageous considering it represents about 0.1seconds of voice traffic data (would you be happy paying £1.80 a minute?) and can be queued.
On the face of it, 10p might sound reasonable compared to the scandalous roaming prices though. However, O2 let you use your bundled SMS allowance when roaming (at a premium) and it surely can't be long before this piracy is legislated into the history books.