<p>I'm starting a web project that likely should be fine with SQLite.  I have SQLObject on top of it, but thinking long term here -- if this project should require a more robust (e.g. able to handle high traffic), I will need to have a transition plan ready.  My questions:</p>

<ol>
<li>How easy is it to transition from one DB (SQLite) to another (MySQL or Firebird or PostGre) under SQLObject?  </li>
<li>Does SQLObject provide any tools to make such a transition easier?  Is it simply take the objects I've defined and call createTable?  </li>
<li>What about having multiple SQLite databases instead?  E.g. one per visitor group?  Does SQLObject provide a mechanism for handling this scenario and if so, what is the mechanism to use?</li>
</ol>

<p>Thanks,
Sean</p>

I'm not sure I understand the question.
The
SQLObject documentation
lists six kinds of connections available.  Further, the database connection (or scheme) is specified in a connection string.  Changing database connections from SQLite to MySQL is trivial.  Just change the connection string.
The
documentation
lists the different kinds of schemes that are supported.