PostgreSQL comes with a command line client: psql (http://www.postgresql.org/docs/6.4/static/app-psql.htm)

If you're going to work with a relational database you need to learn SQL and how the relational model works. There's no shortcut that won't just leave you worse off in the long run. SQL was originally designed as an end-user friendly way to work with relational data.

For learning about relational database theory I recommend Chris Date's book "Database In Depth: Relational Theory For Practitioners." There are quite a few good books for learning SQL. For learning the PostgreSQL flavor of SQL the PostgreSQL docs are probably the best place to start.

Thanks for your reply, but that's exactley what I don't want to do. I know about psql and I know how to write SQL statements, but what I'm looking for is a text-based interface that let me perform tasks (similar to what you can do with phpmyadmin) without writing SQL statements.

I'm having a hard time imagining an easier text-based interface to an RDBMS than the command line client. For things I do frequently -- backup a database, dump just the schema, export a view as CSV -- I write shell scripts around psql or the mysql CLI. You can use command-line parameters and hide the psql options and commands that you don't want to look up over and over. Obviously you could do the same thing with other tools if you don't like sh/bash scripting.