Basically I've added CLI support to my script for being able to download threads and sections (boards, in the 4chan slang) more easily. See some examples and download the code in http://code.krenel.org/4chan/src . If you find a bug or think that something can be improved, just leave a comment, thanks ;)

1. Download a single thread:

inedit@tpad:~/ python 4chanV2.py -t
http://boards.4chan.org/o/res/6355428  
Downloading thread in ./imgs/thread_6355428  (36 images found)  
D: http://images.4chan.org/o/src/1338935975006.jpg  
D: http://images.4chan.org/o/src/1338935097459.jpg  
D: http://images.4chan.org/o/src/1338907819188.jpg

[...] cutted [...]

2. Download all the threads of the first page of a board:

inedit@tpad:~$ python 4chanV2.py -b http://boards.4chan.org/o  
** Parsing pages in http://boards.4chan.org/b/  
Number of threads found: 16

Downloading thread in ./imgs/thread_404482027  (211 images found)  
D: http://images.4chan.org/b/src/1338995473830.png  
D: http://images.4chan.org/b/src/1339015275815.jpg  
D: http://images.4chan.org/b/src/1339012366921.jpg

[...]

Downloading thread in ./imgs/thread_404492271  (5 images found)

[...]

3. Download all the threads of the first three pages of a board (remember that the first page starts with zero).

inedit@tpad:~$ python 4chanV2.py -b http://boards.4chan.org/o -p
0,1,2  
** Parsing pages in http://boards.4chan.org/b/  
Number of threads found: 36

Downloading thread in ./imgs/thread_404482027  (211 images found)  
D: http://images.4chan.org/b/src/1338995473830.png  
D: http://images.4chan.org/b/src/1339015275815.jpg  
D: http://images.4chan.org/b/src/1339012366921.jpg

[...]

Downloading thread in ./imgs/thread_404492271  (5 images found)

[...]

4. Prevent downloading twice the images on the same thread. This allows you to resume downloads after some time without having to download everithing again:

inedit@tpad:~/$ python 4chanV2.py -t
http://boards.4chan.org/o/res/6355428#q6355428  
Downloading thread in ./imgs/thread_6355428  (36 images found)  
Image already downloaded (cached)!  
Image already downloaded (cached)!  
Image already downloaded (cached)!

[...]

5. Be able to give a name to the directory where the photos are stored:

inedit@tpad:~ python 4chanV2.py -t
http://boards.4chan.org/o/res/6355428#q6355428 -n boobs  
Downloading thread in ./imgs/thread_boobs  (36 images found)  
D: http://images.4chan.org/o/src/1338935975006.jpg  
D: http://images.4chan.org/o/src/1338935097459.jpg  
D: http://images.4chan.org/o/src/1338907819188.jpg

[...]

6. Use the interactive mode. Don't really know what are you going to download? Use the interactive mode, check the link and choose if you want to download the thread or not. Very useful when using the -b/--board (note that the board can be passed as parameter as an URL or just the name of the board).

inedit@tpad:~$ python 4chanV2.py -b o -i  
** Parsing pages in http://boards.4chan.org/b/  
Number of threads found: 16  
Found thread http://boards.4chan.org/b/res/404492271 with 3 images. Do
yo want to download it? [y/N/q] n  
Found thread http://boards.4chan.org/b/res/404495554 with 4 images. Do
yo want to download it? [y/N/q] n  
Found thread http://boards.4chan.org/b/res/404482027 with 211 images.
Do yo want to download it? [y/N/q] y  
Image already downloaded (cached)!  
Image already downloaded (cached)!  
Image already downloaded (cached)!

7. See the help on the CLI:

inedit@tpad:$ python 4chanV2.py --help  
Usage: 4chanV2.py [options]

Options:  
-h, --help            show this help message and exit  
-t URL, --thread=URL  Download the given thread.  
-n NAME, --name=NAME  Store the thread with the given name. Use it
with  
--thread.  
-b URL, --board=URL   Download the given board.  
-p PAGE_NUMBER, --page=PAGE_NUMBER  
Specify the number of the pages we want to download.  
Used with --board. The pages must be separated by  
comas: 1,2,3.  
-i, --interactive     Ask you for confirmation before download a
thread.  
Very useful when using --board.  
-v LOG_LEVEL, --verbose=LOG_LEVEL  
Be more or less verbose. 4 is very berbose and 0 is  
only error messages. The default output is verbose 4