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: Does the <h1> tag get more SEO value if there is no usable keyword in the URL?
Answer: Keywords are not needed in the domain name for a page to rank for that keyword.   Even keywords in the URL path don't help much (see Are keywords in URLs good SEO or needlessly redundant?)

The page title (&lt;title&gt;) is the place where words give the most ranking weight.  Other usages on the page can also help.   

It is important to note that overusing a keyword can actually hurt rankings.   Using a keyword once in the title, once in the h1, and once in the page body is enough.   Using the keyword more than that is unlikely to help rankings.   Using the keyword more than that in ways that make the text awkward to read can cause keyword stuffing penalties.