Having the ability to insert a column in the middle of a table using the PGAdmin 3 UI would be very nice. Benefits include grouping related fields and creating a column list in the natural flow of data entry. Having it automated within the UI would make this piece of DB management so much easier.
What are you asking for here?
A) For pgAdmin to run a complex algorithm to physcially re-order columns by creating a new table?
B) For PostgreSQL itself to allow for column re-ordering?
The later has been discussed many times, including relatively recently, but hasn't made it into -core (not even sure if patches have been proposed.
The data entry aspect can be handled quite readily without any interaction with the physical table. Having pgAdmin or some other application maintain an ordering table that defaults to physical but can be overridden would be a somewhat trivial project compared to what you propose.
