9 hour layover in Singapore
 

Hoping to make the best of it. Any suggestions for breakfast or lunch and any sights close to the airport?

You can take a free tour, just head to the Free Tour desks in the transit lounge. If you don't want to go on the tour I would strongly suggest getting yourself a ticket on the MRT with a guide map and just have a free and easy time. Even close to the airport, just a few stations along you can get to East Park area, or head down to orchard Road, try City Hall Interchange as a good landmark station for other areas, shopping around Bugis Street Station is excellent. Tghe MRT is reliable, cheap, fast. In fact they have a very good website, cannot recall the URL but just do a search for 'mrt singapore'. Lots of information and you can plan your own tour based on the MRT network.
have fun!

Fantastic! thanks James. Have looked at the MRT website and it's very helpful:
http://www.smrtcorp.com/smrt/index_travel_time.htm

Will I have to convert cash to Singapore Dollars, or is US currency accepted? I suppose changing $10 for a day's excursion isn't such a hassle.

We had the exact same layover, and had plenty of time to walk around Orchard Road, have dinner on the Quai, and a Singapore Sling at Raffles (a tourist trap, but fun anyway!).

You have plenty of time, so just read up on the highlights and make a plan for what you want to see. We live in China and have traveled around Asia quite a bit, so were less interested in Chinatown and Little India, and more interested in the antique stores (and the Barnes and Noble!!), but you should have enough time to identify 1 or 2 things/areas you want to see and have a good visit!

You will need Singapore $, change in transit lounge or arrivals. I would change about US$60.

Andrea, I always head to the booshop at Wheelock, junction of Scotts and Orchard, I spend vast amounts of money on books and magazines to take back to Thailand!

JamesA - Oooh, great tip!! I LOVE going to Hong Kong because they have a bookstore in arrivals and another one as soon as you depart the Airport Express in Central! Lack of English language books is one of the only drawbacks of being an expat . . . can't tell you how many suitcases of books I've lugged back to China!