Ask HN: Recommended sites for advertising tech jobs

I work for a small Irish web startup (12 employees). We're currently trying to fill 2 new positions -- a PHP developer, based in Ireland, and an implementation consultant, based in our San Diego office. (The implementation consultant is essentially a support specialist who would also provide web-based training and other services.) Up until now, we've mostly recruited through friends/referrals, agencies ($$$) and some Irish jobs sites (jobs.ie, etc.), but I was hoping the HN community might be able to offer some better suggestions. Any advice would be greatly appreciated! Thanks!