Well actually there are lots of things or products we can already buy using Bitcoin. As what you have said, you already mentioned travel tickets which is made possible through online booking because there are already aviation services or traveling services that accepts Bitcoin as payment. The capacity and capability of you to use your Bitcoin into buying goods and services actually depends first into the community you are into because there are countries where there is a limitation for using Bitcoin since there are only few merchants who have already adapted Bitcoin usage. You can buy many things using Bitcoin by surfing into online shops because I supposed since it is online transaction and if you want to pay it directly, you can use up Bitcoin for that.