Slow running site – excessive number of queries

Hi, my site has started taking forever to load (like over 20 seconds at times on a broadband connection). At first i thought it must be server related but when i looked at the source code for my home page i noticed this
<!-- 1768 queries. 13.544 seconds. -->

That seems to be a ridiculous amount of db queries ?, i don’t really have a lot going on on the home page and have only 8 plugins enabled.

Could this be something to do with the number of pages, links or link categories i have ?

Any help would be appreciated.