Enable a navigation block for each taxonomy category and enable the possibility to set a base link for each block links passing the term id as parameter.
If you are in a node that contains one or more terms that are in that navigation block it will mark those term links as active.
If you are in the base path you set (taxonomy/term/$tid by default) plus the term id it will be mark as active in the block.
You can enable any number of navigation blocks and control them as any other block.Installation
Unpack and copy inside /sites/all/modules directory or /modules/ directory.
Activate from Administer > Site Building > Modules
Requirements:
· Drupal 5.x ONLY.