It looks like the voice actor for Toad has changed over time.
From this Wiki:
Toad's voice was originally portrayed by Tomoko Maruno for the Japanese version of Mario Kart 64 (and later the first three Mario Party titles) and Isaac Marshall for the overseas version. Eventually, Jen Taylor, and then Kelsey Hutchinson, played Toad's voice for many ...
I found this here:
They reappear in New Super Mario Bros. Wii with the same function as in New
Super Mario Bros.. But when the player collects them all in a level
before they disappear, the audience cheers. They are often arranged in
patterns. Blue Coins also appear in New Super Mario Bros. 2.
I found that collecting all of them normally ...
Enemies turn golden when Mario/Luigi touches a Gold Ring. In this state, the enemies will give you coins when defeated instead of points and may spawn coins while they are alive (e.g. throwing coins at you).
You can find the specific behaviours for each enemy at MarioWiki
I have gotten a StreetPass for a course pack that I don't have. Here's what it looks like:
It's locked, just like those records which contain levels that I haven't beat yet. It displays the normal ???? for coins, and says Course pack not downloaded instead of where it normally says the course pack name. If I press "A" to challenge that record, I get an ...
Getting to a Star Toad House (the yellow ones) will give you a Gold Flower.
You can also stuff a Gold Flower into your inventory if you collect a Mega Mushroom or an Invincibility Leaf while gold. Then all you have to do is finish the level.
Gold Flowers that are obtained within stages always expire at the end of that stage. The exception to that rule is Gold Flowers retrieved from Star Toad Houses, which are automatically deposited into your lower screen's inventory when you visit that Toad House. Star Toad Houses are the yellow Toad Houses that you see on the overworld map, contrasting the ...
I just saw this today, which is a video describing a trick whereby you can get 30,000 coins in 2 minutes by exploiting a well-placed turtle and vine in a hidden area above world 3-4.
It appears that there's some sort of cap at 30,000 coins, which prevents the total going over this. You'd have to repeat this trick around ...