Twitter searching is a bit rubbish, it now only shows the last 4 days of tweets. You can Google stuff instead though. This is starting to make Google Plus even more attractive.

To search on Twitter you use

http://search.twitter.com

if you put in adam foster lotus

http://twitter.com/#!/search/adam%20foster%20lotus

you will be surprised and horrified to see "There are no Top Tweets for adam foster lotus"

which is frankly ridiculous.

So a better way to search is:

http://www.google.co.uk/#sclient=psy&hl=en&source=hp&q=site%3Atwitter.com%2FAdamFoster+Lotus&fp=6f27533496c659e0&bav=on.2,or.r_gc.r_pw.&cad=b&filter=0

The site%3A is site: which is twitter.com/adamfoster then + the keywords "Lotus" and add &filter=0 on the end to get all results.