Whoah! I forgot to subscribe to my thread and didn't know I got so many replies. Thank you all.
Gastronamie - I have no idea what you mean about the name of this thread. It clearly shows 'Shape Water' effective 10 seconds ago.
Douche - I totally forgot about Pykrete! Writing that one up now. For anyone who doesn't know about that stuff, you should watch Mythbusters reruns sometime.
I'm seeing a lot of people wanting to directly freeze other people with the cantrip. It's kind of depressing - you know this won't work in even the most unreasonable game, right? I'm looking for good ideas and not just gamebreaking ones.
To anyone else, feel free to add on with other ideas.