diff --git a/src/calibre/ebooks/conversion/cli.py b/src/calibre/ebooks/conversion/cli.py
index fa1b4056db..0b5c15b3f0 100644
--- a/src/calibre/ebooks/conversion/cli.py
+++ b/src/calibre/ebooks/conversion/cli.py
@@ -233,14 +233,18 @@ def create_option_parser(args, log):
 
     return parser, plumber
 
+def abspath(x):
+    if x.startswith('http:') or x.startswith('https:'):
+        return x
+    return os.path.abspath(os.path.expanduser(x))
+
 def main(args=sys.argv):
     log = Log()
     parser, plumber = create_option_parser(args, log)
     opts = parser.parse_args(args)[0]
-    y = lambda q : os.path.abspath(os.path.expanduser(q))
     for x in ('read_metadata_from_opf', 'cover'):
         if getattr(opts, x, None) is not None:
-            setattr(opts, x, y(getattr(opts, x)))
+            setattr(opts, x, abspath(getattr(opts, x)))
     recommendations = [(n.dest, getattr(opts, n.dest),
                         OptionRecommendation.HIGH) \
                                         for n in parser.options_iter()
diff --git a/src/calibre/ebooks/conversion/plumber.py b/src/calibre/ebooks/conversion/plumber.py
index 9bb3a71c03..339f1f92ec 100644
--- a/src/calibre/ebooks/conversion/plumber.py
+++ b/src/calibre/ebooks/conversion/plumber.py
@@ -424,7 +424,7 @@ OptionRecommendation(name='author_sort',
 
 OptionRecommendation(name='cover',
     recommended_value=None, level=OptionRecommendation.LOW,
-    help=_('Set the cover to the specified file.')),
+    help=_('Set the cover to the specified file or URL')),
 
 OptionRecommendation(name='comments',
     recommended_value=None, level=OptionRecommendation.LOW,
@@ -638,6 +638,20 @@ OptionRecommendation(name='timestamp',
                         continue
                 setattr(mi, x, val)
 
+    def download_cover(self, url):
+        from calibre import browser
+        from PIL import Image
+        from cStringIO import StringIO
+        from calibre.ptempfile import PersistentTemporaryFile
+        self.log('Downloading cover from %r'%url)
+        br = browser()
+        raw = br.open_novisit(url).read()
+        buf = StringIO(raw)
+        pt = PersistentTemporaryFile('.jpg')
+        pt.close()
+        img = Image.open(buf)
+        img.convert('RGB').save(pt.name)
+        return pt.name
 
     def read_user_metadata(self):
         '''
@@ -655,6 +669,8 @@ OptionRecommendation(name='timestamp',
             mi = MetaInformation(opf)
         self.opts_to_mi(mi)
         if mi.cover:
+            if mi.cover.startswith('http:') or mi.cover.startswith('https:'):
+                mi.cover = self.download_cover(mi.cover)
             mi.cover_data = ('', open(mi.cover, 'rb').read())
             mi.cover = None
         self.user_metadata = mi