I'm also a Giles owner, and I'm also trying to shop him. However, that's not really because I think he's bad - it's more because I'd be satisfied starting Rickie Weeks and am in desperate need for a closer...
However, I think that Giles is bound to start hitting at some pont. He's been pretty average up until now, but considering how poorly the Braves' lineup as a whole has been hitting, I suspect that there's still time for him to turn it around, especially once the Braves start heating up.
Still, I definitely wouldn't pay close to full value for him. (By "full value," I mean fourth-to-sixth round pick value.) I traded BJ Ryan for him earlier in the year, and I've regretted it every day since. (Well, almost every day since - I didn't regret it that night he got three SB.

)
In a keeper, he's obviously got a bit more value as a young player. However - and others can feel free to correct me if I'm wrong about this - I'm not sure his ceiling is too high. I see him as a scrappy player who tries his hardest on every play and is very capable of putting up 20-25-.300, but with limited potential to do much beyond that. That's certainly valuable at second base, but the problem is that because I don't see him as a guy whose raw talent is overwhelming, he's also capable of putting up a season around 12-20-.280, which is nothing spectacular.
(Of course, I'll admit that by only estimating his HR and SB and ignoring his R and RBI, I'm glossing over part of what makes him so valuable, which is his lineup spot. As long as he's hitting in the 2-spot, he'll get a lot more opportunities for runs and RBI's than the average second baseman.)
So basically, he's a guy I'd be more than happy to buy low on, but I wouldn't pay
too much.