Oil Cleansing Method!! I've been using this for a while and it's the best thing I've done. I used olive oil or grapeseed oil with Castor oil (this is the cleansing part!). It has really reduced the size of my pores and doesn't dry my skin out.
Have a look at this and also at this huge but very informative thread.
agree about OCM, or perhaps using a facial oil as a night time moisturiser.
But as a cover-up, try a silicone-based primer underneath your base: I like Estee Lauder Idealist (? or perhaps Perfectionist - I can't remember which is the primer), Clinique pore perfector, and Chanel Le Blanc de Chanel (think that is limited edition though), not so fond of the Clarins in the little red tub but other people like it.
Basically it acts like polyfilla and makes everything smooth (as well as hiding redness etc). Put foundation or tinted moisturiser on top but be careful applying it as some combinations of base + primer 'pill' into little balls
I love clinique pore minimising instant perfector. I have awful open pores, acne scars etc, and this covers them so nicely. My skin just looks polished. It sort of glosses over all of the bad things and leaves my skin looking and feeling really smooth too. In fact, I feel as though I'm always talking about it because I think it's so great and I think everybody should try it. It doesn't exactly close your pores (I'm not sure that a cream could really do that), but it certainly makes them less noticable and kind of hides them away. Here are hundreds of reviews, mostly agreeing that it's great. Not too expensive either.