PostgreSQL Migration of databases 7.2 to 7.4

Hello All,

We have a server in our datacentre running PostgreSQL 7.2 with about 50
databases set up (for different customers). We have just commissioned a
much better specified server which is running PostgreSQL 7.4.

We need to migrate the databases from 7.2 to 7.4. The smallest database
contains about 200K of data whilst the largest database weighs in at
about 100Mb.

What's the best way to migrate the data? Would you suggest using the
pgdump tools? We've found them to be quite problematic in use and are
not entirely sure of the best command line switches to use.

We need to make sure the data and permissions get migrated, as the data
is being used for live web sites. So obviously speed of migration is
important as we will have a period of downtime to complete the
migrations.

Any suggestions/product ideas would be greatly appreciated.
Thanks in advance,

Mario