GROUP BY & column not in select list

Hi,

is there any way to cheat group by -statement or make the query in
other way? I mean that query:

SELECT userid, name, MAX(age) FROM users GROUP BY name;

produces list of the oldest users grouped by the name, but the
userid is also available (this way it is not valid at all).

Table contains rows:
....
12 | Jack | 18
13 | Jim   | 22
14 | Jack | 56
....

and the query above should return:
13 | Jim   | 22
14 | Jack | 56

Keen to know if there is solution!

Regards,

anssi