Hi I thanks to all the advice I could get odbc to work in squeak on my mac.
In case its useful to someone this are the steps:

0 I'm supposing you have an odbc dsn working using iodbc (the default 
mac driver, samething for unixodbc), and you downloaded the odbc client 
package from squeakMap

1 from a terminal create an odbc.framework directory.
(sudo mkdir /System/Library/Frameworks/odbc.framework)

2 symlink the iodbc library into the newly created directory
ln -s /usr/lib/libiodbc.dylib \
  /System/Library/Frameworks/odbc.framework/libiodbc

3 in squeak browse ODBCLibrary class, change the method moduleName to:
moduleName
	"Return the name of the module for this library"
	^ 'libiodbc.framework'

4 inspect ODBCLibrary class and do "default _ nil" (do it) in the 
inspector. This class is a Singleton and you want the new instance to 
load the new moduleName.

5 try the ODBCConnection examples!


Thanks to all who helped me out!
/diego