Is it safe to +1 my own sites with google's new +1 button. I've added this button to my web pages but would there be any detrimental effect of clicking this link myself and +1 my own pages?
Go for it. If you like your own content, there seems little reason (beyond retaining some sense of modesty) not to recommend it to your friends.
There's no logical reason for Google to penalise you for plus-one-ing1 your own sites, just as there's no logical reason for Facebook to penalise you for liking your own Facebook page. Google +1 is currently used only to provide recommendations within search results for people Google thinks you may know, not to increase your position.
As such, the only thing clicking +1 on your sites will do is to put your name next to your site if a person Google thinks is connected to you (e.g. a user logged into Gmail who you've contacted before) does a search that results in your site appearing in the results.
It's possible that Google may use +1 as part of their ranking algorithm in future but, even if they did, a single recommendation from one user -- regardless of who it is -- is unlikely to make much difference anyway.
1: There must be a better verb for this, but I can't think of one.
Found the answer - you can't +1 yourself. The box simple turns red and has a ! in it. Looks like they just don't allow people to +1 sites that belong to themselves. I found out by clicking on my links. Either you can't +1 yourself or my +1 box doesn't work.