Yes Alt/Command �(depending your OS) + m to find implementors and Alt + n to find senders.
I found this post from Mariano very usefull�http://marianopeck.wordpress.com/2012/05/19/pharo-tips-and-tricks/

And, yes, I'm working in adding smart suggestions and smart menus depending where you have the cursor :).
Right now I have a prototype that offers you a small set of actions associated to your selection (a custom menu is displayed with alt + t), but still lot of work is missing. �I've sent an email a couple of days before.



2013/4/16 Damien Cassou <damien.cassou@gmail.com>
On Tue, Apr 16, 2013 at 2:11 PM, dimitris chloupis <thekilon@yahoo.co.uk> wrote:
> What I mean is that while browsing a method, if I found a message and
> wanted to browse its code �i could highlight
> with my mouse (select the text) right click and select "browse" from the
> menu.


As Esteban says, it is under the "Extended search" submenu. You can
also press Alt+m to do the same.

--
Damien Cassou
http://damiencassou.seasidehosting.st

"Success is the ability to go from one failure to another without
losing enthusiasm."
Winston Churchill