Just yesterday I used this phrase in a text. My massage therapist texted me to say she had to cancel my appointment due to a family emergency. I responded, "Thanks for letting me know. Take care!" What else can one say in a situation like that?! I didn't know what was going on, and figured it wasn't my business to be asking too many questions right then. Later, I learned her mother was just diagnosed with cancer and there are a lot of appointments and unknowns looming in the future, both for her and her mother. My heart goes out to them both.
"Take care." It's a very useful phrase. It can be said to people who aren't close enough for an "I love you," yet it still gets the point across that someone is concerned. It can be spoken to someone who is about to try something risky, whether it is a financial risk, or an emotional risk, or trying to jump across the Grand Canyon on a motorcycle. Which makes me wonder: how often did Evel Knievel's mother say that to him?!
I hope my 5 minutes are up. I can't think of anything else.