Most definitely! I belong to a network of guest bloggers that do this.
Its one of the few back-linking building techniques that Google doesn't frown upon.
it's a win win win situation
as long as you provide unique and useful content then Google is happy.
The webmaster is happy because Google is happy; plus his or her visitors get fresh and useful content on a particular topic or niche.
And you are happy; because not only do you get one or two DO FOLLOW back links but you get them from a different source then your usual article directory and hopefully the PR of the guest blog that you are blogging on is relatively high.
And in turn Google is happy with you and rewards you with higher rankings.
It truly is a cyclical symbiotic relationship for all three parties involved.
I'll go so far as to say it's the best way to build back links!
I have around 19 reputable blogs on several different niches and topics.
If you'd like to guest blog for me just contact me via hubs.
take care and have a nice day