On Monday in Poland starts new MVNO - tuBiedronka. It will work on Era network. Its owner is discount network called
"Biedronka" (ladybird). It has over 1350 shops in Poland. Offer seems very good - 0,33 PLN per minute to all networks excluding Play (but on phone line /+48727383838, works only in Era and Polish Telecom/ they say it's promotion valid to 30.06.2009). SMS - 0,14 PLN. Other rates are unknown until Monday.