import urllib
import lxml.html

def get_pages(url):
    page = lxml.html.parse(urllib.urlopen(url))
    mp3 = page.xpath("//a[contains(@href, '.mp3')]")
    for item in mp3: print item.get('href')
    nextpage = page.xpath("//span[text()='Next']/..")
    if nextpage: get_pages(nextpage[0].get('href'))

get_pages("http://thehistoryofrome.typepad.com/")