Interesting wallpaper behind the toilet...luxury hand towel.

Any specific examples dclostboy?

How about hanging a fun decal in the powder room. It will bring a smile and are easily removable when you want a change. Very reasonably priced;)
http://www.houzz.com/photos/bath/decals-

Depends on the look you'd want to go for. Found these on Houzz. All would work and all give a different vibe.

I love the tree decal and I think you have a wall for it!

Cost easy, replace the mirror with a square one (same size) with dark wood frame ($20-$30) at HomeGoods. They also have a square one with mother of pearl square tiles in it that also has your blue paint color in it. Replace towel rack with a shelf (dark wood or chrome) and put a unique/fancy holder with the folded individual paper hands towels. $5 for 100 at Walmart. Remove the extra tissue and toilet brush and put a long tall picture over the toilet.

Go dramatic Moroccan. Paint the walls a warm coral or turquoise. Replace the over mirror fixture with a hanging light.

I love the wall paper idea! Such a small amount would bring so much impact. I also like the change out the mirror idea (if you can remove without damage - should be on brackets - hopefully, no glue of sorts). If wall paper is not your thing, stencils have come along way and you can just paint over when tired of it. The most important thing is to add pattern to that space. The colors & choices presented are wonderful. Some great art would be fun. Create a collage of sorts on the wall where the towel rod is now. Moving the towel rod to the wall with switches and a smaller scale - ring of sorts - decorative would make much more sense.

If you want to make if fun for your guests consider putting a chalk board space, framed like in the example picture.

Another way you could go is to put up crown molding and ceiling treatment. Just adding dimension to the space. Could also add floating shelves above the toilet area spanning the width to create some interesting reflection, other than the toilet.

Mix it all if you so chose. So many ideas. Good luck.

You guys are all amazing! Thanks for the fantastic recommendations!

Does anyone know where i can buy some thin vases with a nice fake plant in it?

Cambridge do you know where you found that floating shelf photo? Id love to replicate it

Faux wood blinds are a great choice for bathroom- they can withstand humidity and they look just like their more expensive counterpart.

Bali...where to hang the blinds, as not a single window in the room?

sorry about that- I made an incorrect assumption that there were windows in this bathroom.

I think plants would make a great, low cost addition for sprucing up your bathroom

Saad, what did you do? Pics please!

Closing the lid will go a long way, removing the spare toilet paper, removing the toilet brush, nice new towel (btw your towel bar feels too high), nice countertop soap dispenser (or soap dish) rather then the plastic thing from the store. I would not clutter the space (it is tiny already) but I would put nice pictures on the wall.

Agree with others .. I would wallpaper.

This paper is Schumacher Modern Trellis Wallpaper
http://www.fschumacher.com/search/ProductDetail.aspx?sku=5003280