I'll admit that I have no idea who Oliver is in the world of British politics and political literature, though it's obvious he's a very powerful intellect with a flair for easily read prose. I stumbled into his blog through following random links (always a fun thing to do) and have been reading him ever since. He's a self-described Classical Liberal, but he also supports the War in Iraq. Yeah, he writes mostly about British Liberal Democratic politics, but he also covers other topics, and it's all readable.
He recently posted twice (First post here and second post here.) on the idea of liberty, in the positive and negative senses. They're great, short reading, especially the second one.