The following dialog is selected from The Italian Job:
Where'd you say you got these?
I didn't.
A little walking around money.
I guess I'm not walking as far as I thought.
I was wondering what the bolded phrase means.
I might think it doesn't imply street money or pocket money here. Sort of black money or what, in this context.
Here is what happened in the scene. To keep things simple, I will describe the scene in present tenses.
In the story, Steve is selling his gold to Yevhen (the first guy), who is a gangster. (If I recall correctly, his gold is in the form of gold bars stolen from another gang which in turn stole the gold from the original owner.) Yevhen gets the gold and puts it in a safe place. Before giving money to Steve, Yevhen gets curious about the gold and asks Steve,
Yevhen: Where'd you say you got these?
Steve: I didn't.
(Yevhen brings out a box. There is lots of money inside the box.)
Yevhen: A little walking around money.
(Yevhen hands the box over to Steve. Steve gets the box, opens it, and looks inside the box.)
Steve (looking upset): I guess I'm not walking as far as I thought.
So in this movie script, walking around money simply means pocket money. It's a deliberate play on words (which is something usual in movie scripts).
Yevhen could say, "Here is your money," but that isn't what a gangster would say. Also (in my opinion), "walking around money" was used deliberately, so that Steve could say the punchline "I guess I'm not walking as far as I thought," which is a pun on the idiom "walking around money". He was complaining that the amount of money in the box was less than what he wanted.
I am expanding on TylerJamesYoung's comment, I myself did not know what " walking around money" meant. But once I visited the link provided by Tyler I think I get the perspective of the conversation in question.
Lets assume this conversation happening in a hypothetical situation where someone gets caught up with by a policeman.
policeman : Where did you say you got these? (referring to the cash the person has on him)
person : I didn't
person : A little walking around money (he says that the cash is supposed to be a little pocket money)
person : I guess I am not walking as far as I thought (He acknowledges the fact that he might have to hand over the money to the officer, and jokes/plays with the meaning of the word " walking" and says that he thought he would be taking the money with him further than the current distance)
In this scenario, the money could be black / illegal money or the policeman could be corrupt trying to get the money by force or misuse of authority and the money could actually be pocket money and legit. But I guess you get the drift, the meaning of the phrase is just as Tyler pointed out to be - " pocket money " but the context of usage depends on the preceding conversation details.
walk·ing-a·round mon·ey
noun
1. money that is carried on the person for routine expenses and minor emergencies; pocket money.
Source: Dictionary.com – definition of “walking around money”
The idea is that it's enough money to take care of minor needs during a routine footwalk. (If you get thirsty, you at least have enough money buy a drink, for example.)
Another phrase with a similar meaning is pin money. From NOAD:
pin money
noun
1. a small sum of money for spending on inessentials.
