Captain Jack Harkness: Who has a sonic screwdriver?

The Doctor: I do!

Captain Jack Harkness: Who looks at a screwdriver and thinks, "Ooh, this could be a little more sonic."?

The Doctor: What, you've never been bored? Never had a long night? Never had a lot of cabinets to put up?

The Doctor: Sonic blaster, 51st Century- Weapon factories at Villengard?

Capt. Jack Harkness: Yeah. You've been to the factories?

The Doctor: Once.

Jack: They're gone now, destroyed. Main reactor went critical. Vaporised the lot.

The Doctor: Like I said, once. There's a banana grove there now. I like bananas. Bananas are good.

[Later]

Jack: Nice switch.

The Doctor: Thanks. From the groves at Villengard. Thought it was appropriate.

Jack: There's really a banana grove in the heart of Villengard, and you did that?

The Doctor: Bananas are good.