Best way to get a trending/popular list?

I want to create a field called "What's on your mind?" where users can
add a short sentence - and wondered if it would be possible to create a
list of what's popular.

Maybe I could put the sentence into an array, remove common words like
'the', 'it', 'you', etc and then use the remainder of the words to some
how create a 'trending' list?

So say, 10 people add to their profile what's on their mind, with 6 of
them saying 'I'm thinking about Christmas shopping', and the others add
something different - how could I get that 'Christmas shopping' is a
trending topic?

Any ideas on the best way to achieve this? I'm a nube so would
appreciate some direction :slight_smile:

Thanks in advance.

Yes, it's called a tag cloud. Do some searching on tag clouds and
rails.