On the website of 7. Czech Ukulele Festival there is already a list of performers, and it looks good :-) We can look forward e.g. for Hula Hut, Muckrackers, Victotoria Vox, Lucky Leles, Molly Lewis, The Rat Pack, The Hot Potato Syncopators, Dead Mans Uke, U-Kúže, Ukeberries, Ecce Uku and many others.
The festival takes place on Jul 26-27, the Friday afternoon will be at Hanspaulka park (Prague 6, free entrance) and Saturday and Sunday traditionally at the Únetice brewery.