Array in userinfo?

If the data that needs to be stored can fit in the limited space available in UserInfo, then yes; although it cannot be in an array form (except 'char' array -- String). What kind of data are you wanting to store? that is, what type of data does the array you wish to save carry? EDIT: Oh, and how big is the array,, also?

You have available to you 5 Strings of 50 characters each. You can store your 'char' array as a String in one of those. You would still have 200 characters of String space available; plus the other 40 characters of the String you just saved 10 characters in, if you concatenate to save and use substrings to split it back up.