The thing I dislike the most about using my netbook when I travel is that on many occasions when I am working I need an optical drive. My netbook and 99% of all others on the market lack an optical drive. The only option is to use an external drive, but most of those are too large and heavy.
Pioneer has announced a new external DVD/CD burner that it aimed at users of netbooks and other computers that lack optical drives called the DVR-XD09. The tiny drive looks more like a CD case than an optical drive.