I think it would be misspelled and mispronounced a lot, so I think it would be better suited as a middle name. I've tended to pronounce it NAH-sih-ka.
The meaning and its mythological roots appeal to me, but unfortunately, I think of the word "nausea." I think it would still make for a cool user name or middle name, though.
Combos:
Zoe Nausicaa - I really like these two together.
Lorelei NausicaaElspeth NausicaaViolet NausicaaViolette NausicaaValerie NausicaaIsabel /
Isabelle /
Isobel NausicaaHope NausicaaNaomi Nausicaa - A fun, alliterative combo.
Willow NausicaaJudith NausicaaSilhouette
Nausicaa - GPish, but I think it's pretty.
Lily NausicaaVerity NausicaaIvy Nausicaa