I noticed handful of printer applications in Android Market (HP, Epson, Canon, Kodak, Brother, Samsung, Lexmark etc) allows user to make LAN printing. But i could not find a
Not sure if you're still looking for a solution, but Google's Cloud Print service is supposed to address the issue.
Haven't tried integrating the code yet, but it's set up as an all-API-compatible Java source file and corresponding XML layout to create a 'PrintDialog' that you can shoot an intent to within your code. Right now they're saying it works better with PDF-formatted documents, and can maybe handle web-friendly image files, so you may need to incorporate some 3rd-party/open-source PDF-generation depending on what you're printing.
Might check out Google's FAQ as well, since it discusses security concerns and what it takes to make non-cloud-aware printers work with the service. (Looks like there's a software dongle that users would have to install themselves.)
Hope that helps.