help with query: advanced ORDER BY...

hi list

here's what i would like to do:

table1:
field0: id
field1: boolean
field2: numeric
field3: varchar

when selecting records from this table, i would like to have different sort
orders depending if field1 is true or false: all records with field1 = true
should be sorted with field2 first then field3, all records having field2 =
false sorted by field3 first then field2.

example:

field0  |  field1 |  field 2 |  field3
-------------------------------------------
1            t           2           b
2            f           1           z
3            t           1           a
4            f            4           a


desired output after sorting
4            f            4           a
2            f           1           z
3            t           1           a
1            t           2           b

is this possible in a single query?

(i hope my explanations make sense ;-))

- thomas