Yeah, the Singapore Airlines thing was a big shock to me when it first happened. The first time I came to Korea I flew with them and was horrified when they went around forcing everyone with bigger or heavier carry-ons to check them. They gave me a tiny little bag that I could fill and take on with me. The rest I had to check. At least it was no extra charge! It was kind of a big problem though, as I was carrying medical supplies that I really couldn't risk losing in a checked-luggage snafu.
However, that inconvenience was totally counterbalanced by my awesome awesome flight experience! Flying economy with them is as good as what I figure 1st class on an American run airline would be like.
Another warning on baggage: DON'T fly Continental! I just came back from a visit home and receive a rude shock that they only allow ONE checked bag. I had to fork over $70 for my other one. I couldn't believe it. ONE CHECKED BAG for a 14 hour 8,000 mile flight? Who are they kidding?! Greedy little B**tards

Another passenger on my flight was sympathizing with me and I mentioned I'd never fly them again because of the charge. Some busybody employee behind the ticket counter butted in and said "We all have choices" is this really nasty tone. I just ignored her, but man, that snarky attitude totally sealed the deal. From now on I'm going to make sure I save up the extra couple hundred it costs to fly one of the Asian run airlines...Sorry for the rant. My point is, you get what you pay for so make sure you check cheap airlines for hidden fees!