I never check my baggage. I travel with one Costco 22" roll-aboard and one laptop bag. The roll-aboard fits in most overhead compartments end-wise so it doesn't hog too much space. I feel a bit guilty when the overhead is smaller and I have to put the roll-aboard in length-wise. Costco.com now has a 20" version, so I may give that one a try.

One disadvantage of not checking the baggage at the ticket counter is the possibility of having to gate check the bag if I'm delayed in boarding a flight. This happened to me one time -- the overheads were full by the time I boarded and I was forced to gate check the roll-aboard. The tags used for gate checks are flimsy and attached with a thin elastic string. The tag tore off during handling, and the bag did not appear at my final destination. I checked every day with Northwest and they could find no trace of the bag. Since this was on the outbound portion of the itinerary, I had to go out and buy clothes each day. After 3 days, I received a call from Delta. Delta had my bag, but they didn't know why they had it since there were no destination tags. Fortunately, my business card was attached to the bag and they called my cell phone, and I was able to retrieve my bag later that day.