Well, doppler managed to convince me to put lighttpd and sqlite on my colocated box in Athens. He is now hosting the infamous dooky.org there. Just to keep up with the cutting-edge webfoo, I moved my typo engine from apache/mysql to lighttpd/sqlite just to see how it works. You can view this effort by going to http://typo-l.involution.com. The main advantage of running lighttpd is that the user has a little more control over the server for web applications than they would with a monolithic apache instance running. The other advantage to lighttpd over apache is that their support for FastCGI is moving faster. The Apache Foundation just announced formal support for FastCGI late last month, and this is one of the reasons that a lot of the Rubynistas are using lighttpd. The other neat trick with lighttpd is that you can proxy it through a Virtual on an Apache http daemon by adding something like this to your httpd.conf.

<Virtualhost *:80>
        ServerName              typo-l.involution.com:80
        ProxyRequests           Off
        ProxyPreserveHost       On
        RewriteEngine           On
        RewriteRule             ^/(.*) http://127.0.0.1:3334/$1 [P,L]
        ProxyPassReverse        / http://127.0.0.1:3334/
</Virtualhost>

As for SQLite, the main advantage I see using this is that it can be embedded in standalone applications, and adminstered totally by a user on a colocated box. So, it allows you to create as many databases as you want and give you full control of them wihtout having root access to the MySQL daemon. I see both of these technologies as a boon to the web hosting business because it completely obliterates the need for running a MySQL server and administering it.