As a side project I built TwitterAudit (which is under a lot of load right now and runs on a 512mb VPS :) to estimate how many followers are real vs how many are fake. It looks at a sample of 5000 followers and about 5 criteria to guess whether a given user is real or fake... check it out!

Labmeeting.com is a relatively new site (compared to Citeulike) for life-science researchers. You can upload all your PDFs and it will automatically determine the associated Pubmed records. You can add papers to multiple folders and it supports fulltext searching (assuming you have uploaded a PDF). It is free for academic users.

You can also read your PDFs from anywhere (through Scribd, embedded into the site).

Check out a sample paper page

You can also import/export citations from/to a bunch of formats (BibTex/RIS/Endnote).

There are a whole bunch of other interesting features on Labmeeting that I didn't mention here, so just check it out.

I think there are a few websites geared towards solving problems with scientific publications (specifically in the life sciences). I think Labmeeting (labmeeting.com) is one of the earliest websites in this field and already has some good functionality for researchers. As a researcher myself, I know that one of the biggest problems is getting scientists to use new tools. Hopefully, when the right tools comes along we will see some big changes in scientific research methods...