[tracker1]

Shift+Enter will usually enter a newline in a message without triggering send... At least that's the convention used most of the time. No guarantees on specific applications, just my own experience with this.

[Joker_vD]

Some applications annoyingly use the opposite convention: Shift+Enter is what commits the entered text, while plain Enter inserts a newline.

[tracker1]

Yeah, it's not always consistent... hell, google voice's sms in the web app will take shift+enter but fail and just submit half the time anyway.