Feature, blob field.
I haven't done a _ton_ of research on this issue, but it should be possible to add a custom field class with the proper column type.  I've added 'blob' as a column type so you can specify `db_field = 'blob'` and it will create the right column.  Looks like with sqlite3 and psycopg2 at least you'll need to wrap the incoming data using `sqlite.Binary` or `psycopg2.Binary` http://stackoverflow.com/questions/3379166/writing-blob-from-sqlite-to-file-using-python and http://initd.org/psycopg/docs/usage.html#adaptation-of-python-values-to-sql-types ... There are also questions as to the proper python type to return.  Since peewee gives you the ability to create custom fields, and because of the apparent complexity, I'm going to close this issue and suggest that users who need this functionality roll their own specific to their use-case.  Sqlite, for example, returns a python buffer object.  Here's an example implementation for sqlite3:

```
class BlobField(Field):
    db_field = 'blob'

    def db_value(self, v):
        return sqlite3.Binary(v)
```

Alternatively, you could use a TextField and just convert data from/to base64 when storing in the database.
 this is not working on 2.0.9 version. I receive a:
KeyError: 'blob'

I added 'blob': 'BLOB', after line 605.
 @trunet, my apologies, I should have posted an update.  This is no longer included by default in peewee.

It shouldn't be difficult to add your own implementation and it might be something I will add down the road:

http://peewee.readthedocs.org/en/latest/peewee/models.html#creating-a-custom-field
 @trunet -- I added a blob field in 3cabdf3f7139cf9283d74bd27a2399ec94a84551
 nice, thank you very much.

i want to save image in database by peewee.
but peewee has not BlobField yet.
