Re: I refer to a non-specified carbonated beverage as a:

[mildside]

I voted "soft drink" as I'm from Australia. Usually mine is a Coke. My wife enjoys a "spider", which is a carbonated drink (often Coke) with ice-cream in it. The other day she had a blue one - I don't know how she does it!

Cheers!

[Phaysis]

Hey, Mildside.

Carbonated drink with ice cream in it? In the states, those're called "floats", and they're delicious! A scoop of vanilla ice cream with cold Coca Cola or, better yet, root beer (Barq's or A&W Root Beer are best) poored on top, and you have a party.

"Spider," eh? I'll add that to my dictionary. Where do you suppose the term comes from?

(P^h) Phaysis (Shawn)
If idle hands are the tools of the devil, are idol tools the hands of god?

[benizi]

From the OED:

spider, n. 4. Austr. slang. A drink consisting of lemonade and brandy or similar ingredients, mixed; a soft drink with ice-cream floating in it.

From the quotations following:

1859 K. CORNWALLIS New World I. 300 Shandy-gaff, or spiders -- the latter to clear their throats of flies as they said.