Smell is sadly under-utilised as a means of evoking a sense of place during roleplaying games.

Of course many games are set in places you'd probably not want to smell very closely...

And: Five second rule.

Transcript

GM: You walk through an alien market. The exotic smells of strange cuisines meet your nostrils.
R2-D2: Meh. Food? Pitiful organic beings.
Jar Jar: Oooh, how long since wesa had breakfast?
GM: Let's see... It took you a couple of hours to walk into town...
Jar Jar: Mesa so hungry! Mesa grabs a big yummy frog and eats it down!
Qui-Gon: Oh, Sally - you don't have to worry about food until we take Fatigue points. The GM will tell us.
Alien Food Stall Owner: Hey, aren't you paying for that?
Jar Jar: Mesa spits it out!
Qui-Gon: Sorry, we don't need it.
Alien Food Stall Owner: Bah!
GM: Let's see where it lands... <roll>
GM: Oooooh.
GM: It lands in a mean-looking alien's soup.
Sebulba: {angrily} Chuba!!
Jar Jar: It'sa okay! Five second rule!