We bought some temporary blinds for the front sash windows from Blinds in a Box. These are in essence paper, folded blinds up to 6m in length. They come in White or Black and to fix them to the window they have a reusable sticky tape across the top which you can peel off and then just stick the blind to the window or frame. It comes off easily (not too easily) without any damage to the window afterwards.
The blinds look ok, our middle bay window pane is wider than one blind, so they recommend using two blinds and cutting them down. This looks ok, not perfect, but they are only temporary blinds. the side panes are narrower than the blinds and we have cut them down. These look fine.
They provide complete privacy, let light through (we have white ones). They can be pegged back up if you want to see out/in etc. The pegs aren't great in quality, one or two keep pinging off which is a bit annoying. However as we have sash windows we've only used the blinds on the bottom half and so don't bother trying to peg them up during the day as we have enough natural light coming in and at night no-one can see over the half blind anyway.
A good idea if like us, you have just moved in, are mid-decorating/building and need a quick fix for privacy. At c. £25 for 3 blinds, they are also economical, easy to use (cutting to size is a bit of a pain, but I am lazy), look quite cool for paper blinds, and do the job they are meant to do.
I picked mine up from the office in Totteridge, but for a delivery charge they will post to you direct. They operate on-line 'www.blindsinabox.com'.
They also appeared on Dragons Den and got a Dragon to make an investment!