javaにはjavascriptやperlのように文字列連結関数:join()がないんでしたね

では、つぎのようなjoinStrs()を用意

String[] msgStrs = {"NO."+ pos + " was clicked.", item.getText1()};
Toast.makeText(getApplicationContext(),
 	       joinStrs("\n",msgStrs),
	       Toast.LENGTH_SHORT).show();

//文字列連結 javascriptのjoin()の代替
String joinStrs(String delimiter, String[] orgStrs){
    String retStr = "";
    if(orgStrs.length == 0) return retStr;
		
    retStr = orgStrs[0];
    for (int i=1; i<orgStrs.length; i++){
         retStr += (delimiter+orgStrs[i]);
    }
    return retStr;
}

2013/5/6追記

org.apache.commons.lang3 のClass StringUtils にjoinやsplit等が用意されています
http://commons.apache.org/proper/commons-lang/javadocs/api-release/index.html