I'd also love this feature.
The ideal solution would be with the api. That may take some serious effort though, so a simpler solution would maybe be to import csv files manually.

/start:

Client,Project,Registered time,Billable time,Amount ()
ClientName,Projectname,00:00:15,,
Studies,That one chemistry class,01:30:00,,

/end

This loses a lot of the data though since the individual entries aren't split, and they may have some value with their individual task names, tags etc..

I'd be a big fan of having Toggl data imports too. I find that combining RescueTime with Toggl manual logs gives a strong correlation and present a lot of interesting insights: http://www.markwk.com/kickass-your-time.html.

As a first step, is it possible to manually import these time time logs?

Thanks for suggesting this great app though the one that I had been using is Replicon time management software. This is really a cool app that can be accessed from anywhere using a web browser. After using Replicon tool, it had been a very nice experience and quite hassle free too. As compared to rest of the tools that I used earlier like Google Calendar etc, it had been the most effective as well as productive app till date.

Replicon time management software - http://www.replicon.com/olp/time-management-software.aspx is definitely a great application that can be easily implemented and has got really cool features that makes it the perfect tool.