SQL Data Modeler

Available from  OTN ..
http://www.oracle.com/technology/products/database/datamodeler/index.html
Can go through http://sueharper.blogspot.com/  for more details on data modeler  and  other  products from   Oracle Database Tools group.


Could not find much time to explore this further.
Guess this is not a free tool as  SQL Developer.

Useful tools

Oracle Query Tools

1.SQLTOOLS 
 A free oracle  query  tool.   

 Faster  and light weight that most of the other Query tools  that I have used .
 I swear this is the best free query tool  I have used .
     

2. SQL Developer ...  

 Free Oracle query tool that can be downloaded  from  OTN  .  

 http://www.oracle.com/technology/products/database/sql_developer/index.html

3.EverNote
A note taking tool with a client that can be installed on the PC as  well as  an online version.
Got a plugin on Firefox , IE , Outlook .. I love  this ...
PC client will sync  the notes with the servers .
You can have offline notebooks also .