MagnetoDebug

Based on robhudson's awesome work (https://github.com/robhudson/django-debug-toolbar) we've created a debug toolbar for Magento. It is installed as a Magento module without hacking Magento's core.

Basic features are implemented and few others will come soon.
FEATURES:
- Basic access restriction implemented (can be turn on/off from Admin / System / Configuration / Advanced / Debug Toolbar, available only for IPS specified in System / Configuration / Developer / Developer Client Restrictions / Allowed IPS)
- Magento module listing; Toggle Magento modules on the fly
- Display peak memory usage, script execution time
- Request information (controller name, action name, cookies variables, session variables, GET and POST variables)
- Models instantiated
- SQL queries executed for current request; ability to see queries' result or queries' execution plan (EXPLAIN)
- List / search Magento configurations
- List layout handles for current request
- List files that contains layout update definitions for a specific handle (NEW / AWESOME).
- List created blocks, their associated templates; Preview templates' source code.
- Quick actions: Toggle template hints, Clear cache, Toggle inline translate

Github: https://github.com/madalinoprea/magneto-debug
Issue Tracker: https://github.com/madalinoprea/magneto-debug/issues
Homepage: http://moprea.ro/2011/apr/7/magento-debug-toolbar/