Hi All,
This post is so that other noobs like me can view step by step instructions on how to do this!

I have created this post as I have found a need to reboot my phone after installing apps but have had to turn it off then hold the power key button to turn back on so a reboot button would be useful for me.
There are instructions on how to do this pretty quickly but it took me about 2 hours to work out as I have zero knowledge of linux & xterminal & root etc etc
I have wanted to do this for ages but as a noob whenever i read the two links i have pasted in below I would give up after a few minutes as it seemed pretty difficult.
I ended up using information from 2 places
http://wiki.maemo.org/Customizing_maemo_for_power_users (Contents of power key menu part)
and
http://talk.maemo.org/showthread.php?t=39565&page=2 (pwngu!n's post)
and from these two sources i was able to successfully add a reboot button to the powerkey menu!


To help other noobs add this button I have provided a noob's instructions for the noobs.
Advanced users please check I have made no mistakes
To all that do this as you probably know be aware messing with stuff in xterminal/gainroot etc etc can f*&k up your N900

Instructions:

1) Ensure you have 'Extra's' repo enabled (if you dont you can enable extra's repo by following the instructions here --> http://theunlockr.com/2009/11/22/how...ur-nokia-n900/ )

2) In app manager find and install 'Rootsh'

3) Run X terminal (you will find it in your applications)

4) type sudo gainroot then press the enter button on your keyboard

5) type cd /etc/systemui then press the enter button on your keyboard

6) Create a backup copy of the systemui file by typing cp systemui.xml systemui.xml.bak (if things mess up i dont know how to use this backup to repair things)

7) type vi systemui.xml then press the enter button on your keyboard (this takes you into an edit mode)

8) Now use the arrow keys on your keyboard to scroll down to the 10th paragraph of text that starts with
<!--
<menuitem priority="20" name="Reboot">
this is the paragraph that you will need to edit a little.

9) press the 'i' button on your keyboard (allows you to begin editing)

10) see at the start of the paragraph the text <!-- you need to delete this by using the arrow keys on your keyboard to navigate to the position so you can press the backspace button on your keyboard to delete the text <!--

11) Now go down the paragraph 4 lines, create a new line by navigating to the end of the line of text text saying </menuitem> and pressing the enter button on your keyboard

12) In that new blank line you have just created type in <!-- (to get the < symbol you will need to hold down the blue shift key then press ctrl key which will bring up a virtual keyboard with the < symbol on it for you to select)

13) now your first 6 lines should look exactly like this:
<menuitem priority="20" name="Reboot">
<return>6</return>
<po>osso-powerup-shutdown</po>
</menuitem>
<!--
<menuitem priority="10" name="Soft poweroff">
(basically what you have done is moved the text <!-- down 4 lines)

14) Now press the Esc button in X Terminal (its on the touchscreen, at the bottom 3rd one across)

15) Now type :wq then press the enter button on your keyboard (this saves the changes you have just made)

16) Now close X Terminal by clicking the X on the touchscreen top right hand corner.

16.5) open X Terminal and type killall systemui then press the enter button on your keyboard (info supplied by tuminoid)
or
17) Turn N900 off

18) Turn N900 on

19) You should now have the reboot button when you press the hard power key once.

Now i would appreciate it if an experienced person checks through these instructions and sticks a seal of approval that what I have wrote is correct before any noobs attempt to use these instructions, If there need to be any changes made to this please PM me and I will edit the post and make the necessary changes.
Thanks