i just found www.linkdiary.com/ and http://www.seozar.com/ . anybody knows anything about these sites? can they harm our site?
I haven't personally used these too, but as with all of these tools it depends how you use them and what you're using them for. Most of the time I'd say don't bother - you might (or might not) get some ranking improvement - but it's likely to be temporary and if you rely on them too much you're liable to get a penalty eventually. As with all of the "grey hat"/"black hat" link building techniques, they're only really suitable if you've got a load of sites and you can easily diversify your risk and take advantage of any short term gain while it lasts.
Not personally used them but would be really interested to hear from someone who has. Can nenver learn too much!!