Adding marks to pdf file?

Hi all,

Are there any free tool to add marks (eg. colorful fluorescence line or circle, colorful text, etc.) to a pdf file?

Thanks in advance

Not free, but damn cheap.

http://www.cutepdf.com/

@Leadwerks: Thanks, but I mean drawing cirle with mouse in pdf file on screen, not on a physical document. So, I don't need a highlight pen.

@Mortiis: Thanks, it is useful to generate pdf file, but given a pdf file, how could I add a circle in pdf visually?

Any ideas?

http://sourceforge.net/projects/pdfedit :)

@Qube: Thanks. Are there any pc version?

They're all for a PC?!?!

Or use open office 3 beta with PDF import extension.

*edit* before you ask, use google if needed :p

Yes, Qube, you are right.
However it requires "cygqt-mt-3.dll"
I have no experience of installing Cygwin.

I went to the official website
http://cygwin.com/
After downloading setup.exe, I tried to use "download without installing" and use "direct connection" and it asked for mirror sites.
According to http://cygwin.com/mirrors.html,
I tried to add "http://kambing.ui.edu/cygwin/" to the list and continue.
setup.bz2 is ok. When it comes to setup.ini, it says it could download it.

How do you obtain Cygwin?
(Without "cygqt-mt-3.dll", it is impossible to run pdfedit.)