Here are all of the dates the Jonas Brothers and Avril are going to play at together.

Monday 26/5/08 Avril Lavigne with Jonas Brothers Carling Academy Glasgow Glasgow
Tuesday 27/5/08 Avril Lavigne with Jonas Brothers Carling Academy Glasgow Glasgow
Saturday 31/5/08 Avril Lavigne with Jonas Brothers Cardiff International Arena Cardiff
Thursday 29/5/08 Avril Lavigne with Jonas Brothers - seated Men Arena Manchester Manchester
Thursday 29/5/08 Avril Lavigne with Jonas Brothers - standing Men Arena Manchester Manchester
Friday 30/5/08 Avril Lavigne with Jonas Brothers - standing NEC Birmingham Birmingham
Friday 30/5/08 Avril Lavigne with Jonas Brothers - seated NEC Birmingham Birmingham
Tuesday 3/6/08 Avril Lavigne with Jonas Brothers - standing Bournemouth International Centre Bournemouth
Tuesday 3/6/08 Avril Lavigne with Jonas Brothers - seated Bournemouth International Centre Bournemouth
Wednesday 4/6/08 Avril Lavigne with Jonas Brothers - seated The O2 London
Wednesday 4/6/08 Avril Lavigne with Jonas Brothers - standing The O2 London

They are ALL in Europe. All of these dates are in the clander part of the site