I am from Argentina. Here, Alida isn't a common name, but I know about 4 or 5 more. The pronunciaton of this name here is with accent in first A. I love my name, really. It's beautiful to me!
Italian actress Alida Valli (May 3, 1921-April 22, 2006), who starred in films such as "The Paradine Case" (1947) and "The Third Man" (1949), was a famous bearer of this name.
Alida Marroni is the new keyboard/vocalist for the Victory Records band "1997." She replaced former band member, Kerri Mack. They're a pretty good band, I think.
Anyways, I think Alida is a pretty name, and it seems pretty unique.