What are the best options that allow running a Linux distribution, such as Ubuntu inside Windows XP, i.e. within a window?

By "best" I mean quick startup time, low memory requirement, good graphical performance, easy access to the main (host) Windows XP file system.

I know about Wubi and standard Ubuntu with the dual boot capability, but I'd prefer to be able to switch from XP to Linux without a reboot.  I know the Linux experience may not be ideal this way, but it would be pefectly good for my needs.

I've downloaded VirtualBox and the latest Ubuntu and will try the virtual machine approach; however are there any specifically customised Linux versions for this purpose?

I think this would be a great way for people new to Linux to get used to the OS while still having the "safety net" of Windows.


Question: Rails undefined method `model_name' for NilClass:Class When trying to render simple_form in a view
Answer: Ok I finally figured this one out. Instead of trying to render it I just added to form directly to view like so:

&lt;%= simple_form_for(@status) do |f| %&gt;
  &lt;%= f.input :content, label: false, input_html: { class: 'forms', id: 'update_box', tabindex: '1', rows: '1' } %&gt;
  &lt;span class="actions"&gt;
   &lt;%= f.submit "Post to Stream", :class =&gt; 'reg_button btn btn-info' %&gt;
  &lt;/span&gt;
&lt;% end %&gt;


and added @status = Status.new to my show method in my Profiles Controller so that it posts correctly:

class ProfilesController &lt; ApplicationController

  def show
    @status = Status.new
    @member = Member.find_by_user_name(params[:id])
    if @member 
        @statuses = @member.statuses.all
        render action: :show
    else
        render file: 'public/404', status: 404, formats: [:html]
    end
  end

end


Hope this helps someone else out.