If you want to get off really cheap, a send station from headroom or somewhere, and a short mini to mini. If you want to spend about $65, search ebay for a low profile, this looks decent:
http://cgi.ebay.com/IPod-IPhone-Ultra-low-profile-LINE-OUT-DOCK-LOD-SPOFC-/180621802503?pt=Other_MP3_Player_Accessories&hash=item2a0de5fc07#ht_2787wt_1141
I ended up with a whiplash used for $75 or $80, just for a touch of cool factor.
These are on the FS, a little spendy, but nice!
http://www.head-fi.org/forum/thread/537591/fs-alo-cryoxsilver-imod-lod
http://www.head-fi.org/forum/thread/537679/qusp-twisted-cables-low-profile-ipod-iphone-lod-w-cryo-parts-silver-scscag-wires
Personally, I like that one on ebay. Search "ipod lod" and a bunch of them come up in a bunch of price points. Short, flexible wires are better in my opinion. I don't like single strand wire - too stiff.
Have fun!