options of multiple blogs in 1 DB/installation

i’d like to give users the ability to write their own blog.

from what i’ve read so far:
1. create multiple WP with shared users table,
2. create multiple instances
3. wpMU
4. “funny” tricks with wp-config.php

i was hoping there’s a way to create (or use existing) custom views for the core WP blog – but filtered by authors.

my question is – if there are plugins or built-in way(s) to show feeds, aggregation, “views”, search etc. based on author/user ?

(everything else is shared, and is already handled out-of-the-box with standard wordpress setup: user creation, moderation, roles, static pages, etc. the users need just individual blogs.)