Neither group I current run has a thief among them (although the Saturday group does have a S&W Monk, which covers most of the needed bases). Therefore, I find a lot of 10' pole tapping (obviously linked to early dungeon maps being gridded out in 10' hexes), axe hacking at locked doors, crow-barring of locked chests and the like.
Oh, and much finding of traps the old fashioned way - "Ouch! Shit! There's a trap here guys!"
All of which leads to the question - of the current list of 4 core classes, which class can the party do without and still get by? (edit: I realize the Thief was a later addition to the core)
I would lean towards the thief, but in actual play I've seen more groups without a cleric of any sort than a thief. Figure that one out?