selecting records X minutes apart - Mailing list pgsql-sql

I have a table that, at a minimum, has ID and timestamp columns.  Records
are inserted into with random IDs and timestamps.  Duplicate IDs are allowed. 

I want to select records grouped by ID, ordered by timestamp that are X minutes
apart. In this case X is 5.

Note, the intervals are not X minute wall clock intervals, they are X minute
intervals from the last accepted record, per-id.

For instance here is some sample input data:

ID    TS (HH:MM)
-------------------
0    20:00
1    20:03
1    20:04
0    20:05
1    20:05
0    20:08
1    20:09
0    20:10

I'd want the select to return:

ID    TS (HH:MM)
-------------------
0    20:00
0    20:05
0    20:10
1    20:03
1    20:09


Does my question make sense?

Thanks in advance,
Wayne