Is the Old Testament used today?

It is used as a source of information about pre-Christian times. But the New Testament is what is most relevant to following God today.

It's misused today, to be sure.

The pages are useful for rolling smoking papers.


Also for toilet paper.

It's popular in Judaism.

Of course, and is very relevant 

Yes. 2 Timothy 3:16,17   ALL scripture is inspired of God and beneficial for teaching, for reproving, for setting things straight, for disciplining in righteousness, so the man of God may be fully competent, completely equipped for every good work.

Even Jesus when on earth quoted from the Hebrew scripture, usually by saying: it is written.
He even quoted the Old Testament when being tempted by Satan.

The whole Bible is beneficial, it always have been, and will continue to be. It must be read in context, studied properly, Humbly meditated on, and then applied to our every day lives.

Read here: https://www.jw.org/finder?wtlocale=E&docid=2007640&srcid=share

Genesis is good background.

The old testament teaches us many valuable lessons about ourselves and the nature and attributes of God. These are just as relevant today as they everywhere. 

No. That's why nobody ever talks about Adam & Eve or Moses freeing the slaves of Egypt.