i know it doesnt by default and and unless ive overlooked something in the wiki/forums theres no tweak. seems like this should be standard. sucks looking something up and having to remember the number and then dial

Agreed this should be as standard. Thats something the iphone does really well.

yes it can. two lines need to be added to the prefs.js file

1. Install leafpad (if you haven't already) (sorry, you have to install it, but it isn't big and can be found from Extras trough application manager)
2.Close all your browser windows
3.Open X Terminal and write
Code:

killall browser (enter)
cd .mozilla/microb (enter)
leafpad prefs.js (enter)

4. Now you should be in a texteditor-window. Scroll to the bottom of the file and then paste the following there:
Code:

user_pref("network.protocol-handler.warn-external.sip", false);
user_pref("network.protocol-handler.warn-external.tel", false);

5. Save your changes and close the leafpad and Terminal -windows
6.Enjoy!

it's from another thread so the credit is theirs.

you can copy-paste the number from microB into the dialer app

1. swipe from the left of the screen in microB so you see a pointer
2. click on the pointer
3. you can select the number
4. ctrl+c
5. open the phone app
6. go to the numpad
7. ctrl+v

After inserting the two lines mentioned you can copy the phone number as you mentioned, type "tel:" in the adress bar of microb and paste the phone number. the phone app will be opened with the phone number ready to be dialled.