@fzesguer: I’d say yes, a cover letter is important even in this situation. Here are some tips…
If you can, find out more information about the positions that are available. Look at the qualifications/experience requirements for those positions and circle/highlight some key words — you want to find the key words that tell you what they’re looking for in a candidate for that position. See if there are commonalities between certain positions…those are key words that you definitely want to touch upon in your cover letter. (“I have experience in [keyword] as demonstrated by [talk about a specific example where you demonstrated this skill/requirement].”) Pick at least 3 or 4 key words to focus upon and use concrete examples of how you meet those qualifications. Then you can justify saying something like “As you can see, my experience is applicable for A, B, C positions within your company.” (something more elegantly worded though.)
If by any chance you are not able to get detailed information about the positions and only have the position titles, then use google to see what types of qualifications those positions might require (maybe look for another pharmaceutical company that has detailed job postings).
I would stay away from saying something along the lines of “I’m a new grad…looking for experience.” That gives off the impression that you’re inexperienced, when you want to make the case that you are a good fit. Instead of new grad, just say “I graduated from XYZ in [month, year].”
Instead of “but would be grateful for any position you think I would be a good fit for,” I would say something that emphasizes that you have qualifications for many of the positions. Maybe close by saying that you would be happy for the opportunity to discuss further the ways in which you can make a valuable contribution to the company, or something like that.
Try googling for examples of cover letters that are more broad or are applicable for multiple positions in the same company. Here are some links from a really quick google search:
The key is to know that yes, cover letters are a pain. But you don’t want to risk not having your resume looked at because you don’t have a cover letter. The point of the cover letter is to market yourself and to put a context to your resume. Think of recruiters as lazy people — they will be happier with you if YOU do the homework for them by taking the key items from your resume and making the connection to how those items relate to the job(s). Good luck!