Have you used MTS free Wikipedia? I overheard they are falsely advertising but actually it costs something. (like only en.wiki is free and data charges apply for images  on the article from commons). I am not very sure on this, anyone who uses MTS can confirm. But i have to disagree with Arjuna and feel data charges have come down significantly over a period of time now though may still not be affordable to a common man on the street when compared to the dead low voice tariff. More and more alternate ways of consuming Wikipedia on mobile needs to be developed. I particularly find the Wikipedia layer on Google maps for mobile useful while exploring unknown territories.