Like most PDAs, Twiki's useful in the environment of a mall electronics store, and maybe an austere modern home, carrying drinks on a tray as he did. But try taking him to a bar, and you've got all kinds of problems. He can barely grasp a $20, he definitely can't reach over the bar, and there's no chance your drinks will survive a journey across a crowded joint with your drinks unguarded at kneecap level. And that's all if Dr. Theopolis doesn't start chatting up girls on the way back to the table. Crichton, on the other metal claw, could do the job for you, but might have more trouble than you on the stairs down to the subway.
Also, thanks for pointing out all the great covers that Tom Jones did. You were right, "Sexbomb" was good, and "Kiss" was fan-freakin-tastic.