I really like bottle.py [1]. I've used it for a couple of different projects; although not fundamentally different from web.py or flask, it seems to just "make sense".

[1] http://bottlepy.org/docs/stable/

An example from their website:

    from bottle import get, post, request

    @get('/login') # or @route('/login')
    def login_form():
        return '''<form method="POST">
                    <input name="name"     type="text" />
                    <input name="password" type="password" />
                  </form>'''

    @post('/login') # or @route('/login', method='POST')
    def login_submit():
        name     = request.forms.get('name')
        password = request.forms.get('password')
        if check_login(name, password):
            return "<p>Your login was correct</p>"
        else:
            return "<p>Login failed</p>"