I know this is cheesy advice, but why not join some kind of local club or class, like art/dance (salsa is good fun), keep fit, whatever takes your fancy. This is a great way to meet people and it's then up to you to make the effort to get to know these people better. Is there a good 'social scene'/ social club where you work that you could get involved in, if you're not already? Many people get stuck in a social rut at some time another, you just need to give yours a kick start. Don't forget to make the effort with your current friends too. I'm sure they would love a break from their children, so suggest going out for a meal or to the cinema, even if they can only do it once a fortnight or so.