Still wondering what I'm talking about? Well, Wikipedia describes it pretty well:
Manhwa has been influenced by the dramatic modern history of Korea and resulted in diversity of forms and genre, but including a mainstream style similar to manga. Distinctive manhwa can be found in editorial comic strips, artistically-oriented works, and webcomics serials.
Typical characteristics of manhwa:
- the style of character designs - manhwa aimed at teenage girls (which make up the majority of English-translated series) have a distinctively angular style of abstraction which contrasts with the more "cute" and rounded style of their Japanese, Chinese and western equivalents. This is the most obvious difference at a glance, but does not necessarily apply to manhwa aimed at boys or adults.
- The face and eyes are often exaggerated in a cartoon style while the figure is more realistic in proportion. 
- the left->to->right direction of the book (still quite obvious, but not very reliable, as some manga and manhua are 'flipped' around to the western way)
- the Korean name of the author/artist - usually double-barreled and with syllables that do not exist in Japanese (usually the most reliable method, the only exceptions being when a culturally-neutral pseudonym is used, or when the artist is of Korean ethnicity but resides in another country such as the USA)
- the untranslated sound effects (not always present) are in hangul, not kana or hanzi.
For now, I will talk about one such Manhwa artist by the name of 'joshclub'. Joshclub's characters have been described as a combination of photographic realism and a soft painterly touch. For some reason, I have found this to be more in common in Manhwa than anime. And there's that weird nose thing they got going on. I dunno, I wish a real manhwa artist would correct me on this.
One thing I can say is that (although I know its wrong to generalize like this) many of the Manhwa artist I've seen have always adopted a more muted color palette, whearas Japan-based artist use more... wild colors?? I don't know. I could be wrong on this, but like you give a flying f**k.
Wow. I think I'll ogle at this guy's art in the near future again. And more manhwa stuff too if you like, Void. What's that? Cat got your tongue? Yeah, I thought so.