How temporary does it need to be? Does it need to have a door? Would you want to place outlets/lighting on it? Non-load bearing partition walls are very easy to construct and you can make them be whatever you want. If it's done correctly at the time of construction the reverse doesn't have to be too painful, just some patching in the best case (of course this depends on where it is built, the floor, access to ceiling joists to tie in to, etc.). Framing lumber and drywall are cheap.

These look great. Any idea how much they cost?

since rent is so expensive in NYC what a lot of people do is convert large rooms such as living rooms into 2 smaller rooms to make it possible for 2 people to share what would otherwise be used as 1 room. This is very common, so there are a lot of companies that put up these temporary walls at the beginning of a rental lease, and take them down at the end of the lease. Makes housing more affordable when you can split a 2 bedroom apartment between 3 people.

google temporary wall, Washington DC - several companies come up

What is a NYC style wall?

We are in need of a NYC style temporary wall to separate a very large bedroom so our kids can have separate bedrooms. Anyone do this in DC?

Many thanks in advance!